1
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Lee WG, Lee JH. A Deterministic Method to Construct a Common Supercell Between Two Similar Crystalline Surfaces. SMALL METHODS 2024:e2400579. [PMID: 39192466 DOI: 10.1002/smtd.202400579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 08/04/2024] [Indexed: 08/29/2024]
Abstract
Here, a deterministic algorithm is proposed, that is capable of constructing a common supercell between two similar crystalline surfaces without scanning all possible cases. Using the complex plane, the 2D lattice is defined as the 2D complex vector. Then, the relationship between two surfaces becomes the eigenvector-eigenvalue relation where an operator corresponds to a transformation matrix. It is shown that this transformation matrix can be directly determined from the lattice parameters and rotation angle of the two given crystalline surfaces with O(log Nmax) time complexity, where Nmax is the maximum index of repetition matrix elements. This process is much faster than the conventional brute force approach (O ( N max 4 ) $O(N_{\mathrm{max}}^4)$ ). By implementing the method in Python code, experimental 2D heterostructures and their moiré patterns and additionally find new moiré patterns that have not yet been reported are successfully generated. According to the density functional theory (DFT) calculations, some of the new moiré patterns are expected to be as stable as experimentally-observed moiré patterns. Taken together, it is believed that the method can be widely applied as a useful tool for designing new heterostructures with interesting properties.
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Affiliation(s)
- Weon-Gyu Lee
- Computational Science Research Center, Korean Institute of Science and Technology (KIST), Seoul, 02792, South Korea
- inCerebro Co., Ltd, Seoul, 06234, South Korea
| | - Jung-Hoon Lee
- Computational Science Research Center, Korean Institute of Science and Technology (KIST), Seoul, 02792, South Korea
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2
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Sestoft JE, Marnauza M, Olsteins D, Kanne T, Schlosser RD, Chen IJ, Grove-Rasmussen K, Nygård J. Shadowed versus Etched Superconductor-Semiconductor Junctions in Al/InAs Nanowires. NANO LETTERS 2024; 24:8394-8401. [PMID: 38865258 PMCID: PMC11249013 DOI: 10.1021/acs.nanolett.4c02055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2024]
Abstract
Hybrid semiconductor-superconductor nanowires have emerged as a cornerstone in modern quantum devices. Integrating such nanowires into hybrid devices typically requires extensive postgrowth processing which may affect device performance unfavorably. Here, we present a technique for in situ shadowing superconductors on nanowires and compare the structural and electronic properties of Al junctions formed by shadowing versus etching. Based on transmission electron microscopy, we find that typical etching procedures lead to atomic-scale surface roughening. This surface perturbation may cause a reduction of the electron mobility as demonstrated in transport measurements. Further, we display advanced shadowing geometries aiding in the pursuit of bringing fabrication of hybrid devices in situ. Finally, we give examples of shadowed junctions exploited in various device geometries that exhibit high-quality quantum transport signatures.
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Affiliation(s)
- Joachim E Sestoft
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Mikelis Marnauza
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Dags Olsteins
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Thomas Kanne
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Rasmus D Schlosser
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - I-Ju Chen
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Kasper Grove-Rasmussen
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Jesper Nygård
- Center for Quantum Devices and Nano-science Center, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
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3
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Badawy G, Bakkers EPAM. Electronic Transport and Quantum Phenomena in Nanowires. Chem Rev 2024; 124:2419-2440. [PMID: 38394689 PMCID: PMC10941195 DOI: 10.1021/acs.chemrev.3c00656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 01/26/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024]
Abstract
Nanowires are natural one-dimensional channels and offer new opportunities for advanced electronic quantum transport experiments. We review recent progress on the synthesis of nanowires and methods for the fabrication of hybrid semiconductor/superconductor systems. We discuss methods to characterize their electronic properties in the context of possible future applications such as topological and spin qubits. We focus on group III-V (InAs and InSb) and group IV (Ge/Si) semiconductors, since these are the most developed, and give an outlook on other potential materials.
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Affiliation(s)
- Ghada Badawy
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Erik P. A. M. Bakkers
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
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4
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Pan XH, Chen L, Liu DE, Zhang FC, Liu X. Majorana Zero Modes Induced by the Meissner Effect at Small Magnetic Field. PHYSICAL REVIEW LETTERS 2024; 132:036602. [PMID: 38307040 DOI: 10.1103/physrevlett.132.036602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 11/28/2023] [Indexed: 02/04/2024]
Abstract
One key difficulty in realizing Majorana zero modes (MZMs) is the required high magnetic field, which causes serious issues, e.g., shrinks the superconducting gap, reduces topological region, and weakens their robustness against disorders. In this Letter, we propose that the Meissner effect can bring the topological superconducting phase to a superconductor/topological-insulator/superconductor (SC/TI/SC) hybrid system. Remarkably, the required magnetic field strength (<10 mT) to support MZMs has been reduced by several orders of magnitude compared to that (>0.5 T) in the previous schemes. Tuning the phase difference between the top and bottom superconductors can control the number and position of the MZMs. In addition, we account for the electrostatic potential in the superconductor/topological-insulator (SC/TI) interface through the self-consistent Schrödinger-Poisson calculation, which shows the experimental accessibility of our proposal. Our proposal only needs a small magnetic field of less than 10 mT and is robust against the chemical potential fluctuation, which makes the SC/TI/SC hybrid an ideal Majorana platform.
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Affiliation(s)
- Xiao-Hong Pan
- School of Physics and Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Hubei Key Laboratory of Gravitation and Quantum Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Wuhan Institute of Quantum Technology, Wuhan, Hubei 430074, China
| | - Li Chen
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, 100084, China
| | - Dong E Liu
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, 100084, China
| | - Fu-Chun Zhang
- Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Xin Liu
- School of Physics and Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Hubei Key Laboratory of Gravitation and Quantum Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Wuhan Institute of Quantum Technology, Wuhan, Hubei 430074, China
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5
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Wang Y, Chen F, Song W, Geng Z, Yu Z, Yang L, Gao Y, Li R, Yang S, Miao W, Xu W, Wang Z, Xia Z, Song HD, Feng X, Wang T, Zang Y, Li L, Shang R, Xue Q, He K, Zhang H. Ballistic PbTe Nanowire Devices. NANO LETTERS 2023. [PMID: 37948302 DOI: 10.1021/acs.nanolett.3c03604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Disorder is the primary obstacle in the current Majorana nanowire experiments. Reducing disorder or achieving ballistic transport is thus of paramount importance. In clean and ballistic nanowire devices, quantized conductance is expected, with plateau quality serving as a benchmark for disorder assessment. Here, we introduce ballistic PbTe nanowire devices grown by using the selective-area-growth (SAG) technique. Quantized conductance plateaus in units of 2e2/h are observed at zero magnetic field. This observation represents an advancement in diminishing disorder within SAG nanowires as most of the previously studied SAG nanowires (InSb or InAs) have not exhibited zero-field ballistic transport. Notably, the plateau values indicate that the ubiquitous valley degeneracy in PbTe is lifted in nanowire devices. This degeneracy lifting addresses an additional concern in the pursuit of Majorana realization. Moreover, these ballistic PbTe nanowires may enable the search for clean signatures of the spin-orbit helical gap in future devices.
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Affiliation(s)
- Yuhao Wang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Fangting Chen
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Wenyu Song
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Zuhan Geng
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Zehao Yu
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Lining Yang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Yichun Gao
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Ruidong Li
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Shuai Yang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Wentao Miao
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Wei Xu
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Zhaoyu Wang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Zezhou Xia
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Hua-Ding Song
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Xiao Feng
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- Frontier Science Center for Quantum Information, Beijing 100084, China
- Hefei National Laboratory, Hefei 230088, China
| | - Tiantian Wang
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- Hefei National Laboratory, Hefei 230088, China
| | - Yunyi Zang
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- Hefei National Laboratory, Hefei 230088, China
| | - Lin Li
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Runan Shang
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- Hefei National Laboratory, Hefei 230088, China
| | - Qikun Xue
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- Frontier Science Center for Quantum Information, Beijing 100084, China
- Hefei National Laboratory, Hefei 230088, China
- Southern University of Science and Technology, Shenzhen 518055, China
| | - Ke He
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- Frontier Science Center for Quantum Information, Beijing 100084, China
- Hefei National Laboratory, Hefei 230088, China
| | - Hao Zhang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
- Frontier Science Center for Quantum Information, Beijing 100084, China
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6
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Wesdorp JJ, Grünhaupt L, Vaartjes A, Pita-Vidal M, Bargerbos A, Splitthoff LJ, Krogstrup P, van Heck B, de Lange G. Dynamical Polarization of the Fermion Parity in a Nanowire Josephson Junction. PHYSICAL REVIEW LETTERS 2023; 131:117001. [PMID: 37774257 DOI: 10.1103/physrevlett.131.117001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 01/22/2023] [Accepted: 07/14/2023] [Indexed: 10/01/2023]
Abstract
Josephson junctions in InAs nanowires proximitized with an Al shell can host gate-tunable Andreev bound states. Depending on the bound state occupation, the fermion parity of the junction can be even or odd. Coherent control of Andreev bound states has recently been achieved within each parity sector, but it is impeded by incoherent parity switches due to excess quasiparticles in the superconducting environment. Here, we show that we can polarize the fermion parity dynamically using microwave pulses by embedding the junction in a superconducting LC resonator. We demonstrate polarization up to 94%±1% (89%±1%) for the even (odd) parity as verified by single shot parity readout. Finally, we apply this scheme to probe the flux-dependent transition spectrum of the even or odd parity sector selectively, without any postprocessing or heralding.
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Affiliation(s)
- J J Wesdorp
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ, Delft, Netherlands
| | - L Grünhaupt
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ, Delft, Netherlands
| | - A Vaartjes
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ, Delft, Netherlands
| | - M Pita-Vidal
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ, Delft, Netherlands
| | - A Bargerbos
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ, Delft, Netherlands
| | - L J Splitthoff
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ, Delft, Netherlands
| | - P Krogstrup
- NNF Quantum Computing Programme, Niels Bohr Institute, University of Copenhagen, Denmark
| | - B van Heck
- Microsoft Quantum Lab Delft, 2628 CJ, Delft, Netherlands
- Leiden Institute of Physics, Universiteit Leiden, Niels Bohrweg 2, 2333 CA Leiden, Netherlands
- Dipartimento di Fisica, Sapienza Università di Roma, P.le Aldo Moro 2, 00185 Roma, Italy
| | - G de Lange
- Microsoft Quantum Lab Delft, 2628 CJ, Delft, Netherlands
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7
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Haxell D, Coraiola M, Hinderling M, ten Kate SC, Sabonis D, Svetogorov AE, Belzig W, Cheah E, Krizek F, Schott R, Wegscheider W, Nichele F. Demonstration of the Nonlocal Josephson Effect in Andreev Molecules. NANO LETTERS 2023; 23:7532-7538. [PMID: 37552598 PMCID: PMC10450812 DOI: 10.1021/acs.nanolett.3c02066] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/24/2023] [Indexed: 08/10/2023]
Abstract
We perform switching current measurements of planar Josephson junctions (JJs) coupled by a common superconducting electrode with independent control over the two superconducting phase differences. We observe an anomalous phase shift in the current-phase relation of a JJ as a function of gate voltage or phase difference in the second JJ. This demonstrates the nonlocal Josephson effect, and the implementation of a φ0-junction which is tunable both electrostatically and magnetically. The anomalous phase shift is larger for shorter distances between the JJs and vanishes for distances much longer than the superconducting coherence length. Results are consistent with the hybridization of Andreev bound states, leading to the formation of an Andreev molecule. Our devices constitute a realization of a tunable superconducting phase source and could enable new coupling schemes for hybrid quantum devices.
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Affiliation(s)
- Daniel
Z. Haxell
- IBM
Research Europe−Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Marco Coraiola
- IBM
Research Europe−Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Manuel Hinderling
- IBM
Research Europe−Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | | | - Deividas Sabonis
- IBM
Research Europe−Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | | | - Wolfgang Belzig
- Fachbereich
Physik, Universität Konstanz, D-78457 Konstanz, Germany
| | - Erik Cheah
- Solid
State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland
| | - Filip Krizek
- Fachbereich
Physik, Universität Konstanz, D-78457 Konstanz, Germany
- Solid
State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland
| | - Rüdiger Schott
- Solid
State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland
| | | | - Fabrizio Nichele
- IBM
Research Europe−Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
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8
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Goswami A, Mudi SR, Dempsey C, Zhang P, Wu H, Zhang B, Mitchell WJ, Lee JS, Frolov SM, Palmstrøm CJ. Sn/InAs Josephson Junctions on Selective Area Grown Nanowires with in Situ Shadowed Superconductor Evaporation. NANO LETTERS 2023; 23:7311-7318. [PMID: 37561818 DOI: 10.1021/acs.nanolett.3c01320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Superconductor-semiconductor nanowire hybrid structures are useful in fabricating devices for quantum information processing. While selective area growth (SAG) offers the flexibility to grow semiconductor nanowires in arbitrary geometries, in situ evaporation of superconductors ensures pristine superconductor-semiconductor interfaces, resulting in strong induced superconductivity in the semiconducting nanowire. In this work, we used high-aspect-ratio SiOx dielectric walls to in situ evaporate islands of superconductor tin on in-plane InAs SAG nanowires. Our technique enables customization in the designs of such hybrid nanostructures, while simultaneously performing the nanowire and superconductor growth without breaking vacuum. Using this technique, we grew super(S)-normal(N)-super(S), NS, and SNSNS junctions. We performed cryogenic electron transport measurements revealing the presence of gate and field tunable supercurrents. We further measured the superconducting gap and critical fields in the hybrid nanostructures and the crossover from 2e to 1e periodicity in the SNSNS junctions as a proof of the usability of these hybrid nanostructures.
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Affiliation(s)
- Aranya Goswami
- Electrical and Computer Engineering Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Sanchayeta R Mudi
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Connor Dempsey
- Electrical and Computer Engineering Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Po Zhang
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Hao Wu
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Bomin Zhang
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - William J Mitchell
- Nanofabrication facility, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Joon Sue Lee
- California NanoSystems Institute, University of California Santa Barbara, Santa Barbara, California 93106, United States
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Sergey M Frolov
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Christopher J Palmstrøm
- Electrical and Computer Engineering Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
- Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States
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9
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Yan S, Su H, Pan D, Li W, Lyu Z, Chen M, Wu X, Lu L, Zhao J, Wang JY, Xu H. Supercurrent, Multiple Andreev Reflections and Shapiro Steps in InAs Nanosheet Josephson Junctions. NANO LETTERS 2023. [PMID: 37450769 DOI: 10.1021/acs.nanolett.3c01450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
We report an experimental study of proximity induced superconductivity in planar Josephson junction devices made from free-standing InAs nanosheets. The nanosheets are grown by molecular beam epitaxy, and the Josephson junction devices are fabricated by directly contacting the nanosheets with superconductor Al electrodes. The fabricated devices are explored by low-temperature carrier transport measurements. The measurements show that the devices exhibit a gate-tunable supercurrent, multiple Andreev reflections, and a good quality superconductor-semiconductor interface. The superconducting characteristics of the Josephson junctions are investigated at different magnetic fields and temperatures and are analyzed based on the Bardeen-Cooper-Schrieffer (BCS) theory. The measurements of the ac Josephson effect are also conducted under microwave radiations with different radiation powers and frequencies, and integer Shapiro steps are observed. Our work demonstrates that InAs nanosheet based hybrid devices are desired systems for investigating the forefront of physics, such as two-dimensional topological superconductivity.
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Affiliation(s)
- Shili Yan
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
| | - Haitian Su
- Beijing Key Laboratory of Quantum Devices, Key Laboratory for the Physics and Chemistry of Nanodevices, and School of Electronics, Peking University, Beijing 100871, China
- Institute of Condensed Matter and Material Physics, School of Physics, Peking University, Beijing 100871, China
| | - Dong Pan
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, China
| | - Weijie Li
- Beijing Key Laboratory of Quantum Devices, Key Laboratory for the Physics and Chemistry of Nanodevices, and School of Electronics, Peking University, Beijing 100871, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Zhaozheng Lyu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Mo Chen
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
| | - Xingjun Wu
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
| | - Li Lu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Jianhua Zhao
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, China
| | - Ji-Yin Wang
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
| | - Hongqi Xu
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
- Beijing Key Laboratory of Quantum Devices, Key Laboratory for the Physics and Chemistry of Nanodevices, and School of Electronics, Peking University, Beijing 100871, China
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10
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Schwarz M, Vethaak TD, Derycke V, Francheteau A, Iniguez B, Kataria S, Kloes A, Lefloch F, Lemme M, Snyder JP, Weber WM, Calvet LE. The Schottky barrier transistor in emerging electronic devices. NANOTECHNOLOGY 2023; 34:352002. [PMID: 37100049 DOI: 10.1088/1361-6528/acd05f] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 04/25/2023] [Indexed: 06/16/2023]
Abstract
This paper explores how the Schottky barrier (SB) transistor is used in a variety of applications and material systems. A discussion of SB formation, current transport processes, and an overview of modeling are first considered. Three discussions follow, which detail the role of SB transistors in high performance, ubiquitous and cryogenic electronics. For high performance computing, the SB typically needs to be minimized to achieve optimal performance and we explore the methods adopted in carbon nanotube technology and two-dimensional electronics. On the contrary for ubiquitous electronics, the SB can be used advantageously in source-gated transistors and reconfigurable field-effect transistors (FETs) for sensors, neuromorphic hardware and security applications. Similarly, judicious use of an SB can be an asset for applications involving Josephson junction FETs.
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Affiliation(s)
| | - Tom D Vethaak
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Vincent Derycke
- Université Paris-Saclay, CEA, CNRS, NIMBE, LICSEN, Gif-sur-Yvette, F-91191, France
| | | | | | | | | | - Francois Lefloch
- University Grenoble Alps, GINP, CEA-IRIG-PHELIQS, Grenoble, France
| | | | | | - Walter M Weber
- Technische Universität Wien, Institute of Solid State Electronics, Vienna, Austria
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11
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Ibabe A, Gómez M, Steffensen GO, Kanne T, Nygård J, Yeyati AL, Lee EJH. Joule spectroscopy of hybrid superconductor-semiconductor nanodevices. Nat Commun 2023; 14:2873. [PMID: 37208316 DOI: 10.1038/s41467-023-38533-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 05/05/2023] [Indexed: 05/21/2023] Open
Abstract
Hybrid superconductor-semiconductor devices offer highly tunable platforms, potentially suitable for quantum technology applications, that have been intensively studied in the past decade. Here we establish that measurements of the superconductor-to-normal transition originating from Joule heating provide a powerful spectroscopical tool to characterize such hybrid devices. Concretely, we apply this technique to junctions in full-shell Al-InAs nanowires in the Little-Parks regime and obtain detailed information of each lead independently and in a single measurement, including differences in the superconducting coherence lengths of the leads, inhomogeneous covering of the epitaxial shell, and the inverse superconducting proximity effect; all-in-all constituting a unique fingerprint of each device with applications in the interpretation of low-bias data, the optimization of device geometries, and the uncovering of disorder in these systems. Besides the practical uses, our work also underscores the importance of heating in hybrid devices, an effect that is often overlooked.
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Affiliation(s)
- A Ibabe
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, Spain
| | - M Gómez
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, Spain
| | - G O Steffensen
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, Spain
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain
| | - T Kanne
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - J Nygård
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - A Levy Yeyati
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, Spain
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain
| | - E J H Lee
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain.
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, Spain.
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12
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Haxell DZ, Cheah E, Křížek F, Schott R, Ritter MF, Hinderling M, Belzig W, Bruder C, Wegscheider W, Riel H, Nichele F. Measurements of Phase Dynamics in Planar Josephson Junctions and SQUIDs. PHYSICAL REVIEW LETTERS 2023; 130:087002. [PMID: 36898094 DOI: 10.1103/physrevlett.130.087002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 09/15/2022] [Accepted: 01/19/2023] [Indexed: 06/18/2023]
Abstract
We experimentally investigate the stochastic phase dynamics of planar Josephson junctions (JJs) and superconducting quantum interference devices (SQUIDs) defined in epitaxial InAs/Al heterostructures, and characterized by a large ratio of Josephson energy to charging energy. We observe a crossover from a regime of macroscopic quantum tunneling to one of phase diffusion as a function of temperature, where the transition temperature T^{*} is gate-tunable. The switching probability distributions are shown to be consistent with a small shunt capacitance and moderate damping, resulting in a switching current which is a small fraction of the critical current. Phase locking between two JJs leads to a difference in switching current between that of a JJ measured in isolation and that of the same JJ measured in an asymmetric SQUID loop. In the case of the loop, T^{*} is also tuned by a magnetic flux.
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Affiliation(s)
- D Z Haxell
- IBM Research Europe-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - E Cheah
- Solid State Physics Laboratory, ETH Zurich, 8093 Zurich, Switzerland
| | - F Křížek
- IBM Research Europe-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
- Solid State Physics Laboratory, ETH Zurich, 8093 Zurich, Switzerland
| | - R Schott
- Solid State Physics Laboratory, ETH Zurich, 8093 Zurich, Switzerland
| | - M F Ritter
- IBM Research Europe-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - M Hinderling
- IBM Research Europe-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - W Belzig
- Fachbereich Physik, Universität Konstanz, D-78457 Konstanz, Germany
| | - C Bruder
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| | - W Wegscheider
- Solid State Physics Laboratory, ETH Zurich, 8093 Zurich, Switzerland
| | - H Riel
- IBM Research Europe-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - F Nichele
- IBM Research Europe-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
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13
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Kousar B, Carrad DJ, Stampfer L, Krogstrup P, Nygård J, Jespersen TS. InAs/MoRe Hybrid Semiconductor/Superconductor Nanowire Devices. NANO LETTERS 2022; 22:8845-8851. [PMID: 36332116 DOI: 10.1021/acs.nanolett.2c02532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Implementing superconductors capable of proximity-inducing a large energy gap in semiconductors in the presence of strong magnetic fields is a major goal toward applications of semiconductor/superconductor hybrid materials in future quantum information technologies. Here, we study the performance of devices consisting of InAs nanowires in electrical contact with molybdenum-rhenium (MoRe) superconducting alloys. The MoRe thin films exhibit transition temperatures of ∼10 K and critical fields exceeding 6 T. Normal/superconductor devices enabled tunnel spectroscopy of the corresponding induced superconductivity, which was maintained up to ∼10 K, and MoRe-based Josephson devices exhibited supercurrents and multiple Andreev reflections. We determine an induced superconducting gap lower than expected from the transition temperature and observe gap softening at finite magnetic field. These may be common features for hybrids based on large-gap, type II superconductors. The results encourage further development of MoRe-based hybrids.
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Affiliation(s)
- Bilal Kousar
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100Copenhagen, Denmark
- Univ. Grenoble Alpes, CNRS, Institut Néel, 38000Grenoble, France
| | - Damon J Carrad
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100Copenhagen, Denmark
- Department of Energy Conversion and Storage, Technical University of Denmark, Fysikvej, Building 310, 2800Kgs. Lyngby, Denmark
| | - Lukas Stampfer
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100Copenhagen, Denmark
| | - Peter Krogstrup
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100Copenhagen, Denmark
| | - Jesper Nygård
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100Copenhagen, Denmark
| | - Thomas S Jespersen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100Copenhagen, Denmark
- Department of Energy Conversion and Storage, Technical University of Denmark, Fysikvej, Building 310, 2800Kgs. Lyngby, Denmark
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14
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Wang Z, Song H, Pan D, Zhang Z, Miao W, Li R, Cao Z, Zhang G, Liu L, Wen L, Zhuo R, Liu DE, He K, Shang R, Zhao J, Zhang H. Plateau Regions for Zero-Bias Peaks within 5% of the Quantized Conductance Value 2e^{2}/h. PHYSICAL REVIEW LETTERS 2022; 129:167702. [PMID: 36306766 DOI: 10.1103/physrevlett.129.167702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
Probing an isolated Majorana zero mode is predicted to reveal a tunneling conductance quantized at 2e^{2}/h at zero temperature. Experimentally, a zero-bias peak (ZBP) is expected and its height should remain robust against relevant parameter tuning, forming a quantized plateau. Here, we report the observation of large ZBPs in a thin InAs-Al hybrid nanowire device. The ZBP height can stick close to 2e^{2}/h, mostly within 5% tolerance, by sweeping gate voltages and magnetic field. We further map out the phase diagram and identify two plateau regions in the phase space. Despite the presence of disorder and quantum dots, our result constitutes a step forward toward establishing Majorana zero modes.
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Affiliation(s)
- Zhaoyu Wang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Huading Song
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
| | - Dong Pan
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, China
| | - Zitong Zhang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Wentao Miao
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Ruidong Li
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Zhan Cao
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
| | - Gu Zhang
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
| | - Lei Liu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, China
| | - Lianjun Wen
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, China
| | - Ran Zhuo
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, China
| | - Dong E Liu
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
- Frontier Science Center for Quantum Information, 100084 Beijing, China
| | - Ke He
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
- Frontier Science Center for Quantum Information, 100084 Beijing, China
| | - Runan Shang
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
| | - Jianhua Zhao
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, China
| | - Hao Zhang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Beijing Academy of Quantum Information Sciences, 100193 Beijing, China
- Frontier Science Center for Quantum Information, 100084 Beijing, China
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15
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Carrad DJ, Stampfer L, Ols Teins DG, Petersen CEN, Khan SA, Krogstrup P, Jespersen TS. Photon-Assisted Tunneling of High-Order Multiple Andreev Reflections in Epitaxial Nanowire Josephson Junctions. NANO LETTERS 2022; 22:6262-6267. [PMID: 35862144 DOI: 10.1021/acs.nanolett.2c01840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Semiconductor/superconductor hybrids exhibit a range of phenomena that can be exploited for the study of novel physics and the development of new technologies. Understanding the origin of the energy spectrum of such hybrids is therefore a crucial goal. Here, we study Josephson junctions defined by shadow epitaxy on InAsSb/Al nanowires. The devices exhibit gate-tunable supercurrents at low temperatures and multiple Andreev reflections (MARs) at finite voltage bias. Under microwave irradiation, photon-assisted tunneling (PAT) of MARs produces characteristic oscillating sidebands at quantized energies, which depend on MAR order, n, in agreement with a recently suggested modification of the classical Tien-Gordon equation. The scaling of the quantized energy spacings with microwave frequency provides independent confirmation of the effective charge, ne, transferred by the nth-order tunneling process. The measurements suggest PAT as a powerful method for assigning the origin of low-energy spectral features in hybrid Josephson devices.
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Affiliation(s)
- Damon James Carrad
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Department of Energy Conversion and Storage, Technical University of Denmark, Fysikvej, Building 310, 2800 Kgs. Lyngby, Denmark
| | - Lukas Stampfer
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Da Gs Ols Teins
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | | | - Sabbir A Khan
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Danish National Metrology Institute, Kogle Alle 5, 2970 Hørsholm, Denmark
| | - Peter Krogstrup
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Thomas Sand Jespersen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Department of Energy Conversion and Storage, Technical University of Denmark, Fysikvej, Building 310, 2800 Kgs. Lyngby, Denmark
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16
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Aksenov SV. Manifestation of Majorana modes overlap in the Aharonov-Bohm effect. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:255301. [PMID: 35354133 DOI: 10.1088/1361-648x/ac62a7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 03/30/2022] [Indexed: 06/14/2023]
Abstract
One of the key features of the Majorana bound states emerging in topological superconducting (SC) wires is increasing oscillations of their energy under the growth of magnetic field or chemical potential due to concomitant enhancement of hybridization of the Majorana mode wave functions initially localized at the opposite edges of the structure. In this study we found that the other consequence of it is a shift of Aharonov-Bohm (AB) oscillations of linear-response conductance in an interference device where two ends of the SC wire connected with a normal contact via non-SC wires (arms). In addition, it is accompanied by an oscillation period doubling. The numerical calculations for the spinful system are supported by the analytical results for different spinless models allowing to track the conductance evolution as the hybridization of the Majorana modes increases. It is shown that since the coupling between the different arms and normal contact is implemented only via the different-type Majoranas the AB oscillations acquire a fundamentalπ/2 shift in comparison with the effect for an analogous system of zero-energy quantum dots.
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Affiliation(s)
- S V Aksenov
- Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Akademgorodok street 50/38, 660036 Krasnoyarsk, Russia
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17
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Stampfer L, Carrad DJ, Olsteins D, Petersen CEN, Khan SA, Krogstrup P, Jespersen TS. Andreev Interference in the Surface Accumulation Layer of Half-Shell InAsSb/Al Hybrid Nanowires. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2108878. [PMID: 35050545 DOI: 10.1002/adma.202108878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/29/2021] [Indexed: 06/14/2023]
Abstract
Understanding the spatial distribution of charge carriers in III-V nanowires proximity coupled to superconductors is important for the design and interpretation of experiments based on hybrid quantum devices. In this letter, the gate-dependent surface accumulation layer of half-shell InAsSb/Al nanowires is studied by means of Andreev interference in a parallel magnetic field. Both uniform hybrid nanowires and devices featuring a short Josephson junction fabricated by shadow lithography, exhibit periodic modulation of the switching current. The period corresponds to a flux quantum through the nanowire diameter and is consistent with Andreev bound states occupying a cylindrical surface accumulation layer. The spatial distribution is tunable by a gate potential as expected from electrostatic models.
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Affiliation(s)
- Lukas Stampfer
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen, 2100, Denmark
| | - Damon J Carrad
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen, 2100, Denmark
| | - Dags Olsteins
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen, 2100, Denmark
| | - Christian E N Petersen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen, 2100, Denmark
| | - Sabbir A Khan
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen, 2100, Denmark
- Microsoft Quantum Materials Lab Copenhagen, Lyngby, 2800, Denmark
| | - Peter Krogstrup
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen, 2100, Denmark
- Microsoft Quantum Materials Lab Copenhagen, Lyngby, 2800, Denmark
| | - Thomas S Jespersen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, Copenhagen, 2100, Denmark
- Department of Energy Conversion and Storage, Technical University of Denmark, Fysikvej, Building 310, Lyngby, 2800, Denmark
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18
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Zhang P, Wu H, Chen J, Khan SA, Krogstrup P, Pekker D, Frolov SM. Signatures of Andreev Blockade in a Double Quantum Dot Coupled to a Superconductor. PHYSICAL REVIEW LETTERS 2022; 128:046801. [PMID: 35148137 DOI: 10.1103/physrevlett.128.046801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 10/01/2021] [Accepted: 01/07/2022] [Indexed: 06/14/2023]
Abstract
We investigate an electron transport blockade regime in which a spin triplet localized in the path of current is forbidden from entering a spin-singlet superconductor. To stabilize the triplet, a double quantum dot is created electrostatically near a superconducting Al lead in an InAs nanowire. The quantum dot closest to the normal lead exhibits Coulomb diamonds, and the dot closest to the superconducting lead exhibits Andreev bound states and an induced gap. The experimental observations compare favorably to a theoretical model of Andreev blockade, named so because the triplet double dot configuration suppresses Andreev reflections. Observed leakage currents can be accounted for by finite temperature. We observe the predicted quadruple level degeneracy points of high current and a periodic conductance pattern controlled by the occupation of the normal dot. Even-odd transport asymmetry is lifted with increased temperature and magnetic field. This blockade phenomenon can be used to study spin structure of superconductors. It may also find utility in quantum computing devices that use Andreev or Majorana states.
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Affiliation(s)
- Po Zhang
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Hao Wu
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Jun Chen
- Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Sabbir A Khan
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Peter Krogstrup
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - David Pekker
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Sergey M Frolov
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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19
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Ritter M, Schmid H, Sousa M, Staudinger P, Haxell DZ, Mueed MA, Madon B, Pushp A, Riel H, Nichele F. Semiconductor Epitaxy in Superconducting Templates. NANO LETTERS 2021; 21:9922-9929. [PMID: 34788993 PMCID: PMC8662718 DOI: 10.1021/acs.nanolett.1c03133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 11/10/2021] [Indexed: 06/13/2023]
Abstract
Integration of high-quality semiconductor-superconductor devices into scalable and complementary metal-oxide-semiconductor compatible architectures remains an outstanding challenge, currently hindering their practical implementation. Here, we demonstrate growth of InAs nanowires monolithically integrated on Si inside lateral cavities containing superconducting TiN elements. This technique allows growth of hybrid devices characterized by sharp semiconductor-superconductor interfaces and with alignment along arbitrary crystallographic directions. Electrical characterization at low temperature reveals proximity induced superconductivity in InAs via a transparent interface.
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Affiliation(s)
- Markus
F. Ritter
- IBM
Research Europe, Säumerstrasse
4, 8803 Rüschlikon, Switzerland
| | - Heinz Schmid
- IBM
Research Europe, Säumerstrasse
4, 8803 Rüschlikon, Switzerland
| | - Marilyne Sousa
- IBM
Research Europe, Säumerstrasse
4, 8803 Rüschlikon, Switzerland
| | | | - Daniel Z. Haxell
- IBM
Research Europe, Säumerstrasse
4, 8803 Rüschlikon, Switzerland
| | - M. A. Mueed
- IBM
Almaden Research Center, San Jose, California 95120, United States
| | - Benjamin Madon
- IBM
Almaden Research Center, San Jose, California 95120, United States
| | - Aakash Pushp
- IBM
Almaden Research Center, San Jose, California 95120, United States
| | - Heike Riel
- IBM
Research Europe, Säumerstrasse
4, 8803 Rüschlikon, Switzerland
| | - Fabrizio Nichele
- IBM
Research Europe, Säumerstrasse
4, 8803 Rüschlikon, Switzerland
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20
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Bjergfelt MS, Carrad DJ, Kanne T, Johnson E, Fiordaliso EM, Jespersen TS, Nygård J. Superconductivity and Parity Preservation in As-Grown In Islands on InAs Nanowires. NANO LETTERS 2021; 21:9875-9881. [PMID: 34807620 DOI: 10.1021/acs.nanolett.1c02487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We report in situ synthesis of crystalline indium islands on InAs nanowires grown by molecular beam epitaxy. Structural analysis by transmission electron microscopy showed that In crystals grew in a tetragonal body-centered crystal structure within two families of orientations relative to wurtzite InAs. The crystalline islands had lengths < 500 nm and low-energy surfaces, suggesting that growth was driven mainly by surface energy minimization. Electrical transport through In/InAs devices exhibited Cooper pair charging, evidencing charge parity preservation and a pristine In/InAs interface, with an induced superconducting gap ∼ 0.45 meV. Cooper pair charging persisted to temperatures > 1.2 K and magnetic fields ∼ 0.7 T, demonstrating that In/InAs hybrids belong to an expanding class of semiconductor/superconductor hybrids operating over a wider parameter space than state-of-the-art Al-based hybrids. Engineering crystal morphology while isolating single islands using shadow epitaxy provides an interesting alternative to previous semiconductor/superconductor hybrid morphologies and device geometries.
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Affiliation(s)
- Martin Saurbrey Bjergfelt
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Damon J Carrad
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Department of Energy Conversion and Storage, Technical University of Denmark, 2800 Kongens Lyngby Denmark
| | - Thomas Kanne
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Erik Johnson
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- DTU Mechanical Engineering, Technical University of Denmark, 2800 Kongens Lyngby Denmark
| | | | - Thomas Sand Jespersen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Department of Energy Conversion and Storage, Technical University of Denmark, 2800 Kongens Lyngby Denmark
| | - Jesper Nygård
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
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21
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Serles P, Arif T, Puthirath AB, Yadav S, Wang G, Cui T, Balan AP, Yadav TP, Thibeorchews P, Chakingal N, Costin G, Singh CV, Ajayan PM, Filleter T. Friction of magnetene, a non-van der Waals 2D material. SCIENCE ADVANCES 2021; 7:eabk2041. [PMID: 34788102 PMCID: PMC8597991 DOI: 10.1126/sciadv.abk2041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Two-dimensional (2D) materials are known to have low-friction interfaces by reducing the energy dissipated by sliding contacts. While this is often attributed to van der Waals (vdW) bonding of 2D materials, nanoscale and quantum confinement effects can also act to modify the atomic interactions of a 2D material, producing unique interfacial properties. Here, we demonstrate the low-friction behavior of magnetene, a non-vdW 2D material obtained via the exfoliation of magnetite, showing statistically similar friction to benchmark vdW 2D materials. We find that this low friction is due to 2D confinement effects of minimized potential energy surface corrugation, lowered valence states reducing surface adsorbates, and forbidden low-damping phonon modes, all of which contribute to producing a low-friction 2D material.
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Affiliation(s)
- Peter Serles
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, Canada
| | - Taib Arif
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, Canada
| | - Anand B. Puthirath
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
| | - Shwetank Yadav
- Department of Materials Science and Engineering, University of Toronto, 184 College St., Toronto, ON M5S 3E4, Canada
| | - Guorui Wang
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, Canada
| | - Teng Cui
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, Canada
| | - Aravind Puthirath Balan
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
- National Graphene Institute (NGI) and School of Chemical Engineering and Analytical Science (CEAS), University of Manchester, Manchester M13 9PL, UK
| | - Thakur Prasad Yadav
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
- Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221 005, India
| | | | - Nithya Chakingal
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
| | - Gelu Costin
- Department of Earth, Environmental and Planetary Sciences, Rice University, Houston, TX 77005, USA
| | - Chandra Veer Singh
- Department of Materials Science and Engineering, University of Toronto, 184 College St., Toronto, ON M5S 3E4, Canada
- Corresponding author. (T.F.); (P.M.A.); (C.V.S.)
| | - Pulickel M. Ajayan
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
- Corresponding author. (T.F.); (P.M.A.); (C.V.S.)
| | - Tobin Filleter
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, Canada
- Corresponding author. (T.F.); (P.M.A.); (C.V.S.)
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22
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Kürtössy O, Scherübl Z, Fülöp G, Lukács IE, Kanne T, Nygård J, Makk P, Csonka S. Andreev Molecule in Parallel InAs Nanowires. NANO LETTERS 2021; 21:7929-7937. [PMID: 34538054 PMCID: PMC8517978 DOI: 10.1021/acs.nanolett.1c01956] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Indexed: 06/13/2023]
Abstract
Coupling individual atoms fundamentally changes the state of matter: electrons bound to atomic cores become delocalized turning an insulating state to a metallic one. A chain of atoms could lead to more exotic states if the tunneling takes place via the superconducting vacuum and can induce topologically protected excitations like Majorana or parafermions. Although coupling a single atom to a superconductor is well studied, the hybridization of two sites with individual tunability was not reported yet. The peculiar vacuum of the Bardeen-Cooper-Schrieffer (BCS) condensate opens the way to annihilate or generate two electrons from the bulk resulting in a so-called Andreev molecular state. By employing parallel nanowires with an Al shell, two artificial atoms were created at a minimal distance with an epitaxial superconducting link between. Hybridization via the BCS vacuum was observed and the spectrum of an Andreev molecule as a function of level positions was explored for the first time.
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Affiliation(s)
- Olivér Kürtössy
- Department
of Physics and Nanoelectronics “Momentum” Research Group
of the Hungarian Academy of Sciences, Budapest
University of Technology and Economics, Budafoki út 8, 1111 Budapest, Hungary
| | - Zoltán Scherübl
- Department
of Physics and Nanoelectronics “Momentum” Research Group
of the Hungarian Academy of Sciences, Budapest
University of Technology and Economics, Budafoki út 8, 1111 Budapest, Hungary
- University
of Grenoble Alpes, CEA, Grenoble INP, IRIG, PHELIQS, 38000 Grenoble, France
| | - Gergö Fülöp
- Department
of Physics and Nanoelectronics “Momentum” Research Group
of the Hungarian Academy of Sciences, Budapest
University of Technology and Economics, Budafoki út 8, 1111 Budapest, Hungary
| | - István Endre Lukács
- Center
for Energy Research, Institute of Technical
Physics and Material Science, Konkoly-Thege Miklós út 29-33, H-1121, Budapest, Hungary
| | - Thomas Kanne
- Center
for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Jesper Nygård
- Center
for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Péter Makk
- Department
of Physics and Nanoelectronics “Momentum” Research Group
of the Hungarian Academy of Sciences, Budapest
University of Technology and Economics, Budafoki út 8, 1111 Budapest, Hungary
| | - Szabolcs Csonka
- Department
of Physics and Nanoelectronics “Momentum” Research Group
of the Hungarian Academy of Sciences, Budapest
University of Technology and Economics, Budafoki út 8, 1111 Budapest, Hungary
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23
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Delaforce J, Sistani M, Kramer RBG, Luong MA, Roch N, Weber WM, den Hertog MI, Robin E, Naud C, Lugstein A, Buisson O. Al-Ge-Al Nanowire Heterostructure: From Single-Hole Quantum Dot to Josephson Effect. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2101989. [PMID: 34365674 DOI: 10.1002/adma.202101989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/31/2021] [Indexed: 06/13/2023]
Abstract
Superconductor-semiconductor-superconductor heterostructures are attractive for both fundamental studies of quantum phenomena in low-dimensional hybrid systems as well as for future high-performance low power dissipating nanoelectronic and quantum devices. In this work, ultrascaled monolithic Al-Ge-Al nanowire heterostructures featuring monocrystalline Al leads and abrupt metal-semiconductor interfaces are used to probe the low-temperature transport in intrinsic Ge (i-Ge) quantum dots. In particular, demonstrating the ability to tune the Ge quantum dot device from completely insulating, through a single-hole-filling quantum dot regime, to a supercurrent regime, resembling a Josephson field effect transistor with a maximum critical current of 10 nA at a temperature of 390 mK. The realization of a Josephson field-effect transistor with high junction transparency provides a mechanism to study sub-gap transport mediated by Andreev states. The presented results reveal a promising intrinsic Ge-based architecture for hybrid superconductor-semiconductor devices for the study of Majorana zero modes and key components of quantum computing such as gatemons or gate tunable superconducting quantum interference devices.
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Affiliation(s)
- Jovian Delaforce
- Institut NEEL UPR2940, Université Grenoble Alpes, CNRS, Grenoble, 38042, France
| | - Masiar Sistani
- Institute of Solid State Electronics, TU Wien, Gußhausstraße 25-25a, Vienna, 1040, Austria
| | - Roman B G Kramer
- Institut NEEL UPR2940, Université Grenoble Alpes, CNRS, Grenoble, 38042, France
| | - Minh A Luong
- Université Grenoble Alpes, CEA, IRIG-DEPHY, F-38054, Grenoble, 38054, France
| | - Nicolas Roch
- Institut NEEL UPR2940, Université Grenoble Alpes, CNRS, Grenoble, 38042, France
| | - Walter M Weber
- Institute of Solid State Electronics, TU Wien, Gußhausstraße 25-25a, Vienna, 1040, Austria
| | | | - Eric Robin
- Université Grenoble Alpes, CEA, IRIG-DEPHY, F-38054, Grenoble, 38054, France
| | - Cecile Naud
- Institut NEEL UPR2940, Université Grenoble Alpes, CNRS, Grenoble, 38042, France
| | - Alois Lugstein
- Institute of Solid State Electronics, TU Wien, Gußhausstraße 25-25a, Vienna, 1040, Austria
| | - Olivier Buisson
- Institut NEEL UPR2940, Université Grenoble Alpes, CNRS, Grenoble, 38042, France
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24
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Stefański P. Sub-gap Fano resonances in a topological superconducting wire with on-site Coulomb interactions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:465602. [PMID: 34388745 DOI: 10.1088/1361-648x/ac1d6d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
We consider theoretically a 1D-semiconducting wire with strong Rashba interaction in proximity withs-wave superconductor, driven into topological phase by external magnetic field. Additionally, we take into account on-site Coulomb interactions inside the wire. The system is modelled by a tight binding Hamiltonian with Rashba hopping term and induceds-wave superconductivity. Calculations are performed utilizing recursive Green's function method, and Coulomb interactions are treated selfconsistently within Hubbard I approximation. For the Hubbard levels residing withinp-wave superconducting gap, particle-hole symmetric four-resonance structure develops in the density of states, apart from Majorana resonance. One pair of particle-hole symmetric resonances is created by the discrete II-Hubbard levels of the particular site, and the second pair of Hubbard sub-bands originates from recursive summation over the sites of the wire. Quantum interference between both types of pairs of states creates in-gap charge-conjugated Fano resonances with opposite asymmetry factors. We demonstrate that when quantum interference is dominated by two-particle tunneling, the Majorana resonance is strongly diminished, while it is not altered when single-particle tunneling dominates in interference process. We also discuss some consequences for experimental distinction of true Majorana states, and show that on-site Coulomb interactions support the appearance of topological phase.
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Affiliation(s)
- Piotr Stefański
- Institute of Molecular Physics of the Polish Academy of Sciences, ul. Smoluchowskiego 17, 60-179 Poznań, Poland
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25
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Heedt S, Quintero-Pérez M, Borsoi F, Fursina A, van Loo N, Mazur GP, Nowak MP, Ammerlaan M, Li K, Korneychuk S, Shen J, van de Poll MAY, Badawy G, Gazibegovic S, de Jong N, Aseev P, van Hoogdalem K, Bakkers EPAM, Kouwenhoven LP. Shadow-wall lithography of ballistic superconductor-semiconductor quantum devices. Nat Commun 2021; 12:4914. [PMID: 34389705 PMCID: PMC8363628 DOI: 10.1038/s41467-021-25100-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 07/19/2021] [Indexed: 11/09/2022] Open
Abstract
The realization of hybrid superconductor-semiconductor quantum devices, in particular a topological qubit, calls for advanced techniques to readily and reproducibly engineer induced superconductivity in semiconductor nanowires. Here, we introduce an on-chip fabrication paradigm based on shadow walls that offers substantial advances in device quality and reproducibility. It allows for the implementation of hybrid quantum devices and ultimately topological qubits while eliminating fabrication steps such as lithography and etching. This is critical to preserve the integrity and homogeneity of the fragile hybrid interfaces. The approach simplifies the reproducible fabrication of devices with a hard induced superconducting gap and ballistic normal-/superconductor junctions. Large gate-tunable supercurrents and high-order multiple Andreev reflections manifest the exceptional coherence of the resulting nanowire Josephson junctions. Our approach enables the realization of 3-terminal devices, where zero-bias conductance peaks emerge in a magnetic field concurrently at both boundaries of the one-dimensional hybrids.
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Affiliation(s)
- Sebastian Heedt
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands. .,Microsoft Quantum Lab Delft, Delft, The Netherlands.
| | | | - Francesco Borsoi
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | | | - Nick van Loo
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Grzegorz P Mazur
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Michał P Nowak
- AGH University of Science and Technology, Academic Centre for Materials and Nanotechnology, Krakow, Poland
| | - Mark Ammerlaan
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Kongyi Li
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Svetlana Korneychuk
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Jie Shen
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - May An Y van de Poll
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Ghada Badawy
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Sasa Gazibegovic
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Nick de Jong
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.,Netherlands Organisation for Applied Scientific Research (TNO), Delft, The Netherlands
| | - Pavel Aseev
- Microsoft Quantum Lab Delft, Delft, The Netherlands
| | | | - Erik P A M Bakkers
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Leo P Kouwenhoven
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.,Microsoft Quantum Lab Delft, Delft, The Netherlands
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26
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Moayedpour S, Dardzinski D, Yang S, Hwang A, Marom N. Structure prediction of epitaxial inorganic interfaces by lattice and surface matching with Ogre. J Chem Phys 2021; 155:034111. [PMID: 34293896 DOI: 10.1063/5.0051343] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
We present a new version of the Ogre open source Python package with the capability to perform structure prediction of epitaxial inorganic interfaces by lattice and surface matching. In the lattice matching step, a scan over combinations of substrate and film Miller indices is performed to identify the domain-matched interfaces with the lowest mismatch. Subsequently, surface matching is conducted by Bayesian optimization to find the optimal interfacial distance and in-plane registry between the substrate and the film. For the objective function, a geometric score function is proposed based on the overlap and empty space between atomic spheres at the interface. The score function reproduces the results of density functional theory (DFT) at a fraction of the computational cost. The optimized interfaces are pre-ranked using a score function based on the similarity of the atomic environment at the interface to the bulk environment. Final ranking of the top candidate structures is performed with DFT. Ogre streamlines DFT calculations of interface energies and electronic properties by automating the construction of interface models. The application of Ogre is demonstrated for two interfaces of interest for quantum computing and spintronics, Al/InAs and Fe/InSb.
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Affiliation(s)
- Saeed Moayedpour
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Derek Dardzinski
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Shuyang Yang
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Andrea Hwang
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Noa Marom
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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27
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Valentini M, Peñaranda F, Hofmann A, Brauns M, Hauschild R, Krogstrup P, San-Jose P, Prada E, Aguado R, Katsaros G. Nontopological zero-bias peaks in full-shell nanowires induced by flux-tunable Andreev states. Science 2021; 373:82-88. [PMID: 34210881 DOI: 10.1126/science.abf1513] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 05/21/2021] [Indexed: 11/02/2022]
Abstract
A semiconducting nanowire fully wrapped by a superconducting shell has been proposed as a platform for obtaining Majorana modes at small magnetic fields. In this study, we demonstrate that the appearance of subgap states in such structures is actually governed by the junction region in tunneling spectroscopy measurements and not the full-shell nanowire itself. Short tunneling regions never show subgap states, whereas longer junctions always do. This can be understood in terms of quantum dots forming in the junction and hosting Andreev levels in the Yu-Shiba-Rusinov regime. The intricate magnetic field dependence of the Andreev levels, through both the Zeeman and Little-Parks effects, may result in robust zero-bias peaks-features that could be easily misinterpreted as originating from Majorana zero modes but are unrelated to topological superconductivity.
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Affiliation(s)
- Marco Valentini
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria.
| | - Fernando Peñaranda
- Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain
| | - Andrea Hofmann
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Matthias Brauns
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Robert Hauschild
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Peter Krogstrup
- Microsoft Quantum Materials Lab and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Kanalvej 7, 2800 Kongens Lyngby, Denmark
| | - Pablo San-Jose
- Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain
| | - Elsa Prada
- Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain.,Departamento de Física de la Materia Condensada, Condensed Matter Physics Center (IFIMAC) and Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Ramón Aguado
- Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain.
| | - Georgios Katsaros
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria.
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28
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Kanne T, Marnauza M, Olsteins D, Carrad DJ, Sestoft JE, de Bruijckere J, Zeng L, Johnson E, Olsson E, Grove-Rasmussen K, Nygård J. Epitaxial Pb on InAs nanowires for quantum devices. NATURE NANOTECHNOLOGY 2021; 16:776-781. [PMID: 33972757 DOI: 10.1038/s41565-021-00900-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 03/11/2021] [Indexed: 05/21/2023]
Abstract
Semiconductor-superconductor hybrids are widely used to realize complex quantum phenomena, such as topological superconductivity and spins coupled to Cooper pairs. Accessing new, exotic regimes at high magnetic fields and increasing operating temperatures beyond the state-of-the-art requires new, epitaxially matched semiconductor-superconductor materials. One challenge is the generation of favourable conditions for heterostructural formation between materials with the desired properties. Here we harness an increased knowledge of metal-on-semiconductor growth to develop InAs nanowires with epitaxially matched, single-crystal, atomically flat Pb films with no axial grain boundaries. These highly ordered heterostructures have a critical temperature of 7 K and a superconducting gap of 1.25 meV, which remains hard at 8.5 T, and therefore they offer a parameter space more than twice as large as those of alternative semiconductor-superconductor hybrids. Additionally, InAs/Pb island devices exhibit magnetic field-driven transitions from a Cooper pair to single-electron charging, a prerequisite for use in topological quantum computation. Semiconductor-Pb hybrids potentially enable access to entirely new regimes for a number of different quantum systems.
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Affiliation(s)
- Thomas Kanne
- Center for Quantum Devices & Nano-Science Center, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
| | - Mikelis Marnauza
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Dags Olsteins
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Damon J Carrad
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Joachim E Sestoft
- Center for Quantum Devices & Nano-Science Center, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Joeri de Bruijckere
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
- Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Lunjie Zeng
- Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Erik Johnson
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Eva Olsson
- Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Kasper Grove-Rasmussen
- Center for Quantum Devices & Nano-Science Center, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Nygård
- Center for Quantum Devices & Nano-Science Center, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
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29
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Pendharkar M, Zhang B, Wu H, Zarassi A, Zhang P, Dempsey CP, Lee JS, Harrington SD, Badawy G, Gazibegovic S, Op Het Veld RLM, Rossi M, Jung J, Chen AH, Verheijen MA, Hocevar M, Bakkers EPAM, Palmstrøm CJ, Frolov SM. Parity-preserving and magnetic field-resilient superconductivity in InSb nanowires with Sn shells. Science 2021; 372:508-511. [PMID: 33858990 DOI: 10.1126/science.aba5211] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 03/13/2021] [Indexed: 11/02/2022]
Abstract
Improving materials used to make qubits is crucial to further progress in quantum information processing. Of particular interest are semiconductor-superconductor heterostructures that are expected to form the basis of topological quantum computing. We grew semiconductor indium antimonide nanowires that were coated with shells of tin of uniform thickness. No interdiffusion was observed at the interface between Sn and InSb. Tunnel junctions were prepared by in situ shadowing. Despite the lack of lattice matching between Sn and InSb, a 15-nanometer-thick shell of tin was found to induce a hard superconducting gap, with superconductivity persisting in magnetic field up to 4 teslas. A small island of Sn-InSb exhibits the two-electron charging effect. These findings suggest a less restrictive approach to fabricating superconducting and topological quantum circuits.
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Affiliation(s)
- M Pendharkar
- Electrical and Computer Engineering, University of California, Santa Barbara, CA 93106, USA
| | - B Zhang
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - H Wu
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - A Zarassi
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - P Zhang
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - C P Dempsey
- Electrical and Computer Engineering, University of California, Santa Barbara, CA 93106, USA
| | - J S Lee
- California NanoSystems Institute, University of California, Santa Barbara, CA 93106, USA
| | - S D Harrington
- Materials Department, University of California, Santa Barbara, CA 93106, USA
| | - G Badawy
- Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | - S Gazibegovic
- Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | | | - M Rossi
- Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | - J Jung
- Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | - A-H Chen
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - M A Verheijen
- Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | - M Hocevar
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France
| | - E P A M Bakkers
- Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
| | - C J Palmstrøm
- Electrical and Computer Engineering, University of California, Santa Barbara, CA 93106, USA.,California NanoSystems Institute, University of California, Santa Barbara, CA 93106, USA.,Materials Department, University of California, Santa Barbara, CA 93106, USA
| | - S M Frolov
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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30
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Fatemi V, Devoret MH. Going with the grains. Science 2021; 372:464. [PMID: 33926940 DOI: 10.1126/science.abd8556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Valla Fatemi
- Department of Applied Physics, Yale University, New Haven, CT 06520, USA.
| | - Michel H Devoret
- Department of Applied Physics, Yale University, New Haven, CT 06520, USA
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31
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Zang Y, Küster F, Zhang J, Liu D, Pal B, Deniz H, Sessi P, Gilbert MJ, Parkin SS. Competing Energy Scales in Topological Superconducting Heterostructures. NANO LETTERS 2021; 21:2758-2765. [PMID: 33792332 PMCID: PMC8155198 DOI: 10.1021/acs.nanolett.0c04648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/16/2021] [Indexed: 05/21/2023]
Abstract
Artificially engineered topological superconductivity has emerged as a viable route to create Majorana modes. In this context, proximity-induced superconductivity in materials with a sizable spin-orbit coupling has been intensively investigated in recent years. Although there is convincing evidence that superconductivity may indeed be induced, it has been difficult to elucidate its topological nature. Here, we engineer an artificial topological superconductor by progressively introducing superconductivity (Nb), strong spin-orbital coupling (Pt), and topological states (Bi2Te3). Through spectroscopic imaging of superconducting vortices within the bare s-wave superconducting Nb and within proximitized Pt and Bi2Te3 layers, we detect the emergence of a zero-bias peak that is directly linked to the presence of topological surface states. Our results are rationalized in terms of competing energy trends which are found to impose an upper limit to the size of the minigap separating Majorana and trivial modes, its size being ultimately linked to fundamental materials properties.
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Affiliation(s)
- Yunyi Zang
- Max
Planck Institute of Microstructure Physics, Halle 06120, Germany
| | - Felix Küster
- Max
Planck Institute of Microstructure Physics, Halle 06120, Germany
| | - Jibo Zhang
- Max
Planck Institute of Microstructure Physics, Halle 06120, Germany
| | - Defa Liu
- Max
Planck Institute of Microstructure Physics, Halle 06120, Germany
| | - Banabir Pal
- Max
Planck Institute of Microstructure Physics, Halle 06120, Germany
| | - Hakan Deniz
- Max
Planck Institute of Microstructure Physics, Halle 06120, Germany
| | - Paolo Sessi
- Max
Planck Institute of Microstructure Physics, Halle 06120, Germany
| | - Matthew J. Gilbert
- University
of Illinois at Urbana−Champaign, Department of Electrical and Computer Engineering, Urbana, Illinois 61820, United States
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32
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Baumgartner C, Fuchs L, Frész L, Reinhardt S, Gronin S, Gardner GC, Manfra MJ, Paradiso N, Strunk C. Josephson Inductance as a Probe for Highly Ballistic Semiconductor-Superconductor Weak Links. PHYSICAL REVIEW LETTERS 2021; 126:037001. [PMID: 33543978 DOI: 10.1103/physrevlett.126.037001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 12/21/2020] [Indexed: 06/12/2023]
Abstract
We present simultaneous measurements of Josephson inductance and dc transport characteristics of ballistic Josephson junctions based upon an epitaxial Al-InAs heterostructure. The Josephson inductance at finite current bias directly reveals the current-phase relation. The proximity-induced gap, the critical current and the average value of the transparency τ[over ¯] are extracted without need for phase bias, demonstrating, e.g., a near-unity value of τ[over ¯]=0.94. Our method allows us to probe the devices deeply in the nondissipative regime, where ordinary transport measurements are featureless. In perpendicular magnetic field the junctions show a nearly perfect Fraunhofer pattern of the critical current, which is insensitive to the value of τ[over ¯]. In contrast, the signature of supercurrent interference in the inductance turns out to be extremely sensitive to τ[over ¯].
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Affiliation(s)
- Christian Baumgartner
- Institut für Experimentelle und Angewandte Physik, University of Regensburg, 93040 Regensburg, Germany
| | - Lorenz Fuchs
- Institut für Experimentelle und Angewandte Physik, University of Regensburg, 93040 Regensburg, Germany
| | - Linus Frész
- Institut für Experimentelle und Angewandte Physik, University of Regensburg, 93040 Regensburg, Germany
| | - Simon Reinhardt
- Institut für Experimentelle und Angewandte Physik, University of Regensburg, 93040 Regensburg, Germany
| | - Sergei Gronin
- Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907, USA
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
| | - Geoffrey C Gardner
- Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907, USA
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 USA
| | - Michael J Manfra
- Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907, USA
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 USA
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
- School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, USA
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA
| | - Nicola Paradiso
- Institut für Experimentelle und Angewandte Physik, University of Regensburg, 93040 Regensburg, Germany
| | - Christoph Strunk
- Institut für Experimentelle und Angewandte Physik, University of Regensburg, 93040 Regensburg, Germany
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33
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Khan SA, Lampadaris C, Cui A, Stampfer L, Liu Y, Pauka SJ, Cachaza ME, Fiordaliso EM, Kang JH, Korneychuk S, Mutas T, Sestoft JE, Krizek F, Tanta R, Cassidy MC, Jespersen TS, Krogstrup P. Highly Transparent Gatable Superconducting Shadow Junctions. ACS NANO 2020; 14:14605-14615. [PMID: 32396328 DOI: 10.1021/acsnano.0c02979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Gate-tunable junctions are key elements in quantum devices based on hybrid semiconductor-superconductor materials. They serve multiple purposes ranging from tunnel spectroscopy probes to voltage-controlled qubit operations in gatemon and topological qubits. Common to all is that junction transparency plays a critical role. In this study, we grow single-crystalline InAs, InSb, and InAs1-xSbx semiconductor nanowires with epitaxial Al, Sn, and Pb superconductors and in situ shadowed junctions in a single-step molecular beam epitaxy process. We investigate correlations between fabrication parameters, junction morphologies, and electronic transport properties of the junctions and show that the examined in situ shadowed junctions are of significantly higher quality than the etched junctions. By varying the edge sharpness of the shadow junctions, we show that the sharpest edges yield the highest junction transparency for all three examined semiconductors. Further, critical supercurrent measurements reveal an extraordinarily high ICRN, close to the KO-2 limit. This study demonstrates a promising engineering path toward reliable gate-tunable superconducting qubits.
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Affiliation(s)
- Sabbir A Khan
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Charalampos Lampadaris
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Ajuan Cui
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Lukas Stampfer
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Yu Liu
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Sebastian J Pauka
- Microsoft Quantum Sydney, The University of Sydney, Sydney, NSW 2006, Australia
| | - Martin E Cachaza
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | | | - Jung-Hyun Kang
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Svetlana Korneychuk
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
| | - Timo Mutas
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Joachim E Sestoft
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Filip Krizek
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Rawa Tanta
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Maja C Cassidy
- Microsoft Quantum Sydney, The University of Sydney, Sydney, NSW 2006, Australia
| | - Thomas S Jespersen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Peter Krogstrup
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
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34
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Larsen TW, Gershenson ME, Casparis L, Kringhøj A, Pearson NJ, McNeil RPG, Kuemmeth F, Krogstrup P, Petersson KD, Marcus CM. Parity-Protected Superconductor-Semiconductor Qubit. PHYSICAL REVIEW LETTERS 2020; 125:056801. [PMID: 32794832 DOI: 10.1103/physrevlett.125.056801] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/09/2020] [Indexed: 06/11/2023]
Abstract
Coherence of superconducting qubits can be improved by implementing designs that protect the parity of Cooper pairs on superconducting islands. Here, we introduce a parity-protected qubit based on voltage-controlled semiconductor nanowire Josephson junctions, taking advantage of the higher harmonic content in the energy-phase relation of few-channel junctions. A symmetric interferometer formed by two such junctions, gate-tuned into balance and frustrated by a half-quantum of applied flux, yields a cos(2φ) Josephson element, reflecting coherent transport of pairs of Cooper pairs. We demonstrate that relaxation of the qubit can be suppressed tenfold by tuning into the protected regime.
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Affiliation(s)
- T W Larsen
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - M E Gershenson
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
| | - L Casparis
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - A Kringhøj
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - N J Pearson
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Theoretische Physik, ETH Zurich, 8093 Zurich, Switzerland
| | - R P G McNeil
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - F Kuemmeth
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - P Krogstrup
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
- Microsoft Quantum Materials Lab-Copenhagen, 2800 Kongens Lyngby, Denmark
| | - K D Petersson
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
| | - C M Marcus
- Center for Quantum Devices and Microsoft Quantum Lab-Copenhagen, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
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35
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Bargerbos A, Uilhoorn W, Yang CK, Krogstrup P, Kouwenhoven LP, de Lange G, van Heck B, Kou A. Observation of Vanishing Charge Dispersion of a Nearly Open Superconducting Island. PHYSICAL REVIEW LETTERS 2020; 124:246802. [PMID: 32639813 DOI: 10.1103/physrevlett.124.246802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 05/15/2020] [Indexed: 06/11/2023]
Abstract
Isolation from the environment determines the extent to which charge is confined on an island, which manifests as Coulomb oscillations, such as charge dispersion. We investigate the charge dispersion of a nanowire transmon hosting a quantum dot in the junction. We observe rapid suppression of the charge dispersion with increasing junction transparency, consistent with the predicted scaling law, which incorporates two branches of the Josephson potential. We find improved qubit coherence times at the point of highest suppression, suggesting novel approaches for building charge-insensitive qubits.
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Affiliation(s)
- Arno Bargerbos
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
| | - Willemijn Uilhoorn
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
| | - Chung-Kai Yang
- Microsoft Quantum Lab Delft, 2600 GA Delft, The Netherlands
| | - Peter Krogstrup
- Microsoft Quantum Materials Lab and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Kanalvej 7, 2800 Kongens Lyngby, Denmark
| | - Leo P Kouwenhoven
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands
- Microsoft Quantum Lab Delft, 2600 GA Delft, The Netherlands
| | - Gijs de Lange
- Microsoft Quantum Lab Delft, 2600 GA Delft, The Netherlands
| | | | - Angela Kou
- Microsoft Quantum Lab Delft, 2600 GA Delft, The Netherlands
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36
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Kringhøj A, van Heck B, Larsen TW, Erlandsson O, Sabonis D, Krogstrup P, Casparis L, Petersson KD, Marcus CM. Suppressed Charge Dispersion via Resonant Tunneling in a Single-Channel Transmon. PHYSICAL REVIEW LETTERS 2020; 124:246803. [PMID: 32639819 DOI: 10.1103/physrevlett.124.246803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 05/15/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate strong suppression of charge dispersion in a semiconductor-based transmon qubit across Josephson resonances associated with a quantum dot in the junction. On resonance, dispersion is drastically reduced compared to conventional transmons with corresponding Josephson and charging energies. We develop a model of qubit dispersion for a single-channel resonance, which is in quantitative agreement with experimental data.
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Affiliation(s)
- A Kringhøj
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - B van Heck
- Microsoft Quantum, Station Q, University of California, Santa Barbara, California 93106-6105, USA
- Microsoft Quantum Lab Delft, Delft University of Technology, 2600 GA Delft, The Netherlands
| | - T W Larsen
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - O Erlandsson
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - D Sabonis
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - P Krogstrup
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
- Microsoft Quantum Materials Lab Copenhagen, Kanalvej 7, 2800 Lyngby, Denmark
| | - L Casparis
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - K D Petersson
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - C M Marcus
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
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37
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Carrad DJ, Bjergfelt M, Kanne T, Aagesen M, Krizek F, Fiordaliso EM, Johnson E, Nygård J, Jespersen TS. Shadow Epitaxy for In Situ Growth of Generic Semiconductor/Superconductor Hybrids. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1908411. [PMID: 32337791 DOI: 10.1002/adma.201908411] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/27/2020] [Accepted: 03/23/2020] [Indexed: 06/11/2023]
Abstract
Uniform, defect-free crystal interfaces and surfaces are crucial ingredients for realizing high-performance nanoscale devices. A pertinent example is that advances in gate-tunable and topological superconductivity using semiconductor/superconductor electronic devices are currently built on the hard proximity-induced superconducting gap obtained from epitaxial indium arsenide/aluminum heterostructures. Fabrication of devices requires selective etch processes; these exist only for InAs/Al hybrids, precluding the use of other, potentially superior material combinations. This work introduces a crystal growth platform-based on 3D structuring of growth substrates-which enables synthesis of semiconductor nanowire hybrids with in situ patterned superconductor shells. The platform eliminates the need for etching, thereby enabling full freedom in the choice of hybrid constituents. All of the most frequently used superconducting hybrid device architectures are realized and characterized. These devices exhibit increased yield and electrostatic stability compared to etched devices, and evidence of ballistic superconductivity is observed. In addition to aluminum, hybrid structures based on tantalum, niobium, and vanadium are presented.
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Affiliation(s)
- Damon J Carrad
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Martin Bjergfelt
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Thomas Kanne
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Martin Aagesen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
- Danish Defence Research Center, Ballerup, 2750, Denmark
| | - Filip Krizek
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
- Department of Spintronics, Institute of Physics, Czech Academy of Sciences, Praha 6, Prague, 162 00, Czech Republic
| | | | - Erik Johnson
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
- Department of Mechanical Engineering, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark
| | - Jesper Nygård
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Thomas Sand Jespersen
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Copenhagen, 2100, Denmark
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38
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Chi F, Fu ZG, Liu J, Li KM, Wang Z, Zhang P. Thermoelectric Effect in a Correlated Quantum Dot Side-Coupled to Majorana Bound States. NANOSCALE RESEARCH LETTERS 2020; 15:79. [PMID: 32297030 PMCID: PMC7158981 DOI: 10.1186/s11671-020-03307-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 03/24/2020] [Indexed: 05/27/2023]
Abstract
We theoretically study the thermoelectric effect in a hybrid device composed by a topological semiconducting nanowire hosting Majorana bound states (MBSs) and a quantum dot (QD) connected to the left and right non-magnetic electrodes held at different temperatures. The electron-electron Coulomb interactions in the QD are taken into account by the non-equilibrium Green's function technique. We find that the sign change of the thermopower, which is useful for detecting the MBSs, will occur by changing the QD-MBS hybridization strength, the direct overlap between the MBSs at the opposite ends of the nanowire, and the system temperature. Large value of 100% spin-polarized or pure spin thermopower emerges even in the absence of Zeeman splitting in the QD or magnetic electrodes because the MBSs are coupled to electrons of only one certain spin direction in the QD due to the chiral nature of the Majorana fermions. Moreover, the magnitude of the thermopower will be obviously enhanced by the existence of MBSs.
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Affiliation(s)
- Feng Chi
- School of Electronic and Information Engineering, University of Electronic Science and Technology of China, Zhongshan Institute, Shiqi District Xueyuan Road No. 1, Zhongshan, 528402, China
| | - Zhen-Guo Fu
- Institute of Applied Physics and Computational Mathematics, No. 6 Huayuan Road, Haidian District, Beijing, 100088, China.
| | - Jia Liu
- School of Science, Inner Mongolia University of Science and Technology, Kundu District Alding Road No. 7, Baotou, 014010, China
| | - Ke-Man Li
- School of Science, Inner Mongolia University of Science and Technology, Kundu District Alding Road No. 7, Baotou, 014010, China
| | - Zhigang Wang
- Institute of Applied Physics and Computational Mathematics, No. 6 Huayuan Road, Haidian District, Beijing, 100088, China
| | - Ping Zhang
- Institute of Applied Physics and Computational Mathematics, No. 6 Huayuan Road, Haidian District, Beijing, 100088, China
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39
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Liu Y, Luchini A, Martí-Sánchez S, Koch C, Schuwalow S, Khan SA, Stankevič T, Francoual S, Mardegan JRL, Krieger JA, Strocov VN, Stahn J, Vaz CAF, Ramakrishnan M, Staub U, Lefmann K, Aeppli G, Arbiol J, Krogstrup P. Coherent Epitaxial Semiconductor-Ferromagnetic Insulator InAs/EuS Interfaces: Band Alignment and Magnetic Structure. ACS APPLIED MATERIALS & INTERFACES 2020; 12:8780-8787. [PMID: 31877013 DOI: 10.1021/acsami.9b15034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Hybrid semiconductor-ferromagnetic insulator heterostructures are interesting due to their tunable electronic transport, self-sustained stray field, and local proximitized magnetic exchange. In this work, we present lattice-matched hybrid epitaxy of semiconductor-ferromagnetic insulator InAs/EuS heterostructures and analyze the atomic-scale structure and their electronic and magnetic characteristics. The Fermi level at the InAs/EuS interface is found to be close to the InAs conduction band and in the band gap of EuS, thus preserving the semiconducting properties. Both neutron and X-ray reflectivity measurements show that the overall ferromagnetic component is mainly localized in the EuS thin film with a suppression of the Eu moment in the EuS layer nearest the InAs and magnetic moments outside the detection limits on the pure InAs side. This work presents a step toward realizing defect-free semiconductor-ferromagnetic insulator epitaxial hybrids for spin-lifted quantum and spintronic applications without external magnetic fields.
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Affiliation(s)
- Yu Liu
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
| | | | - Sara Martí-Sánchez
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra , 08193 Barcelona , Catalonia , Spain
| | - Christian Koch
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra , 08193 Barcelona , Catalonia , Spain
| | - Sergej Schuwalow
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
| | - Sabbir A Khan
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
| | - Tomaš Stankevič
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
| | - Sonia Francoual
- Deutsches Elektronen-Synchrotron DESY , Hamburg 22603 , Germany
| | | | | | | | - Jochen Stahn
- Paul Scherrer Institute , CH-5232 Villigen , Switzerland
| | - Carlos A F Vaz
- Paul Scherrer Institute , CH-5232 Villigen , Switzerland
| | | | - Urs Staub
- Paul Scherrer Institute , CH-5232 Villigen , Switzerland
| | | | - Gabriel Aeppli
- Paul Scherrer Institute , CH-5232 Villigen , Switzerland
- ETH , CH-8093 Zürich , Switzerland
- EPFL , CH-1015 Lausanne , Switzerland
| | - Jordi Arbiol
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra , 08193 Barcelona , Catalonia , Spain
- ICREA , Pg. Lluís Companys 23 , 08010 Barcelona , Catalonia , Spain
| | - Peter Krogstrup
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
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40
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Kringhøj A, Larsen TW, van Heck B, Sabonis D, Erlandsson O, Petkovic I, Pikulin DI, Krogstrup P, Petersson KD, Marcus CM. Controlled dc Monitoring of a Superconducting Qubit. PHYSICAL REVIEW LETTERS 2020; 124:056801. [PMID: 32083909 DOI: 10.1103/physrevlett.124.056801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 12/23/2019] [Indexed: 06/10/2023]
Abstract
Creating a transmon qubit using semiconductor-superconductor hybrid materials not only provides electrostatic control of the qubit frequency, it also allows parts of the circuit to be electrically connected and disconnected in situ by operating a semiconductor region of the device as a field-effect transistor. Here, we exploit this feature to compare in the same device characteristics of the qubit, such as frequency and relaxation time, with related transport properties such as critical supercurrent and normal-state resistance. Gradually opening the field-effect transistor to the monitoring circuit allows the influence of weak-to-strong dc monitoring of a "live" qubit to be measured. A model of this influence yields excellent agreement with experiment, demonstrating a relaxation rate mediated by a gate-controlled environmental coupling.
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Affiliation(s)
- A Kringhøj
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - T W Larsen
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - B van Heck
- Microsoft Quantum, Station Q, University of California, Santa Barbara, California 93106-6105, USA
- Microsoft Quantum Lab Delft, Delft University of Technology, 2600 GA Delft, Netherlands
| | - D Sabonis
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - O Erlandsson
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - I Petkovic
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - D I Pikulin
- Microsoft Quantum, Station Q, University of California, Santa Barbara, California 93106-6105, USA
| | - P Krogstrup
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
- Microsoft Quantum Materials Lab Copenhagen, Kanalvej 7, 2800 Lyngby, Denmark
| | - K D Petersson
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - C M Marcus
- Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
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41
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Ménard GC, Anselmetti GLR, Martinez EA, Puglia D, Malinowski FK, Lee JS, Choi S, Pendharkar M, Palmstrøm CJ, Flensberg K, Marcus CM, Casparis L, Higginbotham AP. Conductance-Matrix Symmetries of a Three-Terminal Hybrid Device. PHYSICAL REVIEW LETTERS 2020; 124:036802. [PMID: 32031865 DOI: 10.1103/physrevlett.124.036802] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Indexed: 06/10/2023]
Abstract
We present conductance-matrix measurements of a three-terminal superconductor-semiconductor hybrid device consisting of two normal leads and one superconducting lead. Using a symmetry decomposition of the conductance, we find that antisymmetric components of pairs of local and nonlocal conductances qualitatively match at energies below the superconducting gap, and we compare this finding with symmetry relations based on a noninteracting scattering matrix approach. Further, the local charge character of Andreev bound states is extracted from the symmetry-decomposed conductance data and is found to be similar at both ends of the device and tunable with gate voltage. Finally, we measure the conductance matrix as a function of magnetic field and identify correlated splittings in low-energy features, demonstrating how conductance-matrix measurements can complement traditional single-probe measurements in the search for Majorana zero modes.
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Affiliation(s)
- G C Ménard
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
- Microsoft Quantum-Copenhagen, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - G L R Anselmetti
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
- Microsoft Quantum-Copenhagen, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - E A Martinez
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
- Microsoft Quantum-Copenhagen, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - D Puglia
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
- Microsoft Quantum-Copenhagen, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - F K Malinowski
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
- Microsoft Quantum-Copenhagen, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - J S Lee
- California NanoSystems Institute, University of California, Santa Barbara, California 93106, USA
| | - S Choi
- Department of Electrical Engineering, University of California, Santa Barbara, California 93106, USA
| | - M Pendharkar
- Department of Electrical Engineering, University of California, Santa Barbara, California 93106, USA
| | - C J Palmstrøm
- California NanoSystems Institute, University of California, Santa Barbara, California 93106, USA
- Department of Electrical Engineering, University of California, Santa Barbara, California 93106, USA
- Materials Department, University of California, Santa Barbara, California 93106, USA
| | - K Flensberg
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - C M Marcus
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
- Microsoft Quantum-Copenhagen, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - L Casparis
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
- Microsoft Quantum-Copenhagen, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - A P Higginbotham
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
- Microsoft Quantum-Copenhagen, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
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42
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Liu Y, Vaitiekėnas S, Martí-Sánchez S, Koch C, Hart S, Cui Z, Kanne T, Khan SA, Tanta R, Upadhyay S, Cachaza ME, Marcus CM, Arbiol J, Moler KA, Krogstrup P. Semiconductor-Ferromagnetic Insulator-Superconductor Nanowires: Stray Field and Exchange Field. NANO LETTERS 2020; 20:456-462. [PMID: 31769993 DOI: 10.1021/acs.nanolett.9b04187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Nanowires can serve as flexible substrates for hybrid epitaxial growth on selected facets, allowing for the design of heterostructures with complex material combinations and geometries. In this work we report on hybrid epitaxy of freestanding vapor-liquid-solid grown and in-plane selective area grown semiconductor-ferromagnetic insulator-superconductor (InAs/EuS/Al) nanowire heterostructures. We study the crystal growth and complex epitaxial matching of wurtzite and zinc-blende InAs/rock-salt EuS interfaces as well as rock-salt EuS/face-centered cubic Al interfaces. Because of the magnetic anisotropy originating from the nanowire shape, the magnetic structure of the EuS phase is easily tuned into single magnetic domains. This effect efficiently ejects the stray field lines along the nanowires. With tunnel spectroscopy measurements of the density of states, we show that the material has a hard induced superconducting gap, and magnetic hysteretic evolution which indicates that the magnetic exchange fields are not negligible. These hybrid nanowires fulfill key material requirements for serving as a platform for spin-based quantum applications, such as scalable topological quantum computing.
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Affiliation(s)
- Yu Liu
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
- Center for Quantum Devices, Niels Bohr Institute , University of Copenhagen , 2100 Copenhagen , Denmark
| | - Saulius Vaitiekėnas
- Center for Quantum Devices, Niels Bohr Institute , University of Copenhagen , 2100 Copenhagen , Denmark
- Microsoft Quantum Lab Copenhagen, Niels Bohr Institute , University of Copenhagen , 2100 Copenhagen , Denmark
| | - Sara Martí-Sánchez
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra, Barcelona , 08193 Catalonia , Spain
| | - Christian Koch
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra, Barcelona , 08193 Catalonia , Spain
| | - Sean Hart
- Stanford Institute for Materials and Energy Sciences , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
- Department of Physics , Stanford University , Stanford , California 94305 , United States
| | - Zheng Cui
- Stanford Institute for Materials and Energy Sciences , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
- Department of Applied Physics , Stanford University , Stanford , California 94305 , United States
| | - Thomas Kanne
- Center for Quantum Devices, Niels Bohr Institute , University of Copenhagen , 2100 Copenhagen , Denmark
| | - Sabbir A Khan
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
- Center for Quantum Devices, Niels Bohr Institute , University of Copenhagen , 2100 Copenhagen , Denmark
| | - Rawa Tanta
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
- Center for Quantum Devices, Niels Bohr Institute , University of Copenhagen , 2100 Copenhagen , Denmark
| | - Shivendra Upadhyay
- Center for Quantum Devices, Niels Bohr Institute , University of Copenhagen , 2100 Copenhagen , Denmark
- Microsoft Quantum Lab Copenhagen, Niels Bohr Institute , University of Copenhagen , 2100 Copenhagen , Denmark
| | - Martin Espiñeira Cachaza
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
- Center for Quantum Devices, Niels Bohr Institute , University of Copenhagen , 2100 Copenhagen , Denmark
| | - Charles M Marcus
- Center for Quantum Devices, Niels Bohr Institute , University of Copenhagen , 2100 Copenhagen , Denmark
- Microsoft Quantum Lab Copenhagen, Niels Bohr Institute , University of Copenhagen , 2100 Copenhagen , Denmark
| | - Jordi Arbiol
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST , Campus UAB, Bellaterra, Barcelona , 08193 Catalonia , Spain
- ICREA , Pg. Lluís Companys 23 , Barcelona , 08010 Catalonia , Spain
| | - Kathryn A Moler
- Stanford Institute for Materials and Energy Sciences , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
- Department of Physics , Stanford University , Stanford , California 94305 , United States
- Department of Applied Physics , Stanford University , Stanford , California 94305 , United States
| | - Peter Krogstrup
- Microsoft Quantum Materials Lab Copenhagen , 2800 Lyngby , Denmark
- Center for Quantum Devices, Niels Bohr Institute , University of Copenhagen , 2100 Copenhagen , Denmark
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43
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Ridderbos J, Brauns M, de Vries FK, Shen J, Li A, Kölling S, Verheijen MA, Brinkman A, van der Wiel WG, Bakkers EPAM, Zwanenburg FA. Hard Superconducting Gap and Diffusion-Induced Superconductors in Ge-Si Nanowires. NANO LETTERS 2020; 20:122-130. [PMID: 31771328 PMCID: PMC6953474 DOI: 10.1021/acs.nanolett.9b03438] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/19/2019] [Indexed: 05/28/2023]
Abstract
We show a hard superconducting gap in a Ge-Si nanowire Josephson transistor up to in-plane magnetic fields of 250 mT, an important step toward creating and detecting Majorana zero modes in this system. A hard gap requires a highly homogeneous tunneling heterointerface between the superconducting contacts and the semiconducting nanowire. This is realized by annealing devices at 180 °C during which aluminum interdiffuses and replaces the germanium in a section of the nanowire. Next to Al, we find a superconductor with lower critical temperature (TC = 0.9 K) and a higher critical field (BC = 0.9-1.2 T). We can therefore selectively switch either superconductor to the normal state by tuning the temperature and the magnetic field and observe that the additional superconductor induces a proximity supercurrent in the semiconducting part of the nanowire even when the Al is in the normal state. In another device where the diffusion of Al rendered the nanowire completely metallic, a superconductor with a much higher critical temperature (TC = 2.9 K) and critical field (BC = 3.4 T) is found. The small size of these diffusion-induced superconductors inside nanowires may be of special interest for applications requiring high magnetic fields in arbitrary direction.
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Affiliation(s)
- Joost Ridderbos
- MESA
+ Institute for Nanotechnology, University
of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Matthias Brauns
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, 2600 GA Delft, The Netherlands
| | - Folkert K. de Vries
- MESA
+ Institute for Nanotechnology, University
of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Jie Shen
- QuTech
and Kavli Institute of Nanoscience, Delft
University of Technology, 2600 GA Delft, The Netherlands
| | - Ang Li
- Department
of Applied Physics, Eindhoven University
of Technology, Postbox 513, 5600 MB Eindhoven, The Netherlands
| | - Sebastian Kölling
- Department
of Applied Physics, Eindhoven University
of Technology, Postbox 513, 5600 MB Eindhoven, The Netherlands
| | - Marcel A. Verheijen
- Department
of Applied Physics, Eindhoven University
of Technology, Postbox 513, 5600 MB Eindhoven, The Netherlands
| | - Alexander Brinkman
- MESA
+ Institute for Nanotechnology, University
of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Wilfred G. van der Wiel
- MESA
+ Institute for Nanotechnology, University
of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Erik P. A. M. Bakkers
- Department
of Applied Physics, Eindhoven University
of Technology, Postbox 513, 5600 MB Eindhoven, The Netherlands
| | - Floris A. Zwanenburg
- MESA
+ Institute for Nanotechnology, University
of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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44
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Zhang H, Liu DE, Wimmer M, Kouwenhoven LP. Next steps of quantum transport in Majorana nanowire devices. Nat Commun 2019; 10:5128. [PMID: 31719533 PMCID: PMC6851108 DOI: 10.1038/s41467-019-13133-1] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 10/18/2019] [Indexed: 11/26/2022] Open
Abstract
Majorana zero modes are localized quasiparticles that obey non-Abelian exchange statistics. Braiding Majorana zero modes forms the basis of topologically protected quantum operations which could, in principle, significantly reduce qubit decoherence and gate control errors at the device level. Therefore, searching for Majorana zero modes in various solid state systems is a major topic in condensed matter physics and quantum computer science. Since the first experimental signature observed in hybrid superconductor-semiconductor nanowire devices, this field has witnessed a dramatic expansion in material science, transport experiments and theory. While making the first topological qubit based on these Majorana nanowires is currently an ongoing effort, several related important transport experiments are still being pursued in the near term. These will not only serve as intermediate steps but also show Majorana physics in a more fundamental aspect. In this perspective, we summarize these key Majorana experiments and the potential challenges.
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Affiliation(s)
- Hao Zhang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, 100084, Beijing, China.
- Beijing Academy of Quantum Information Sciences, 100193, Beijing, China.
- Frontier Science Center for Quantum Information, 100084, Beijing, China.
| | - Dong E Liu
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, 100084, Beijing, China
- Frontier Science Center for Quantum Information, 100084, Beijing, China
| | - Michael Wimmer
- Qutech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, 2600, GA, The Netherlands
| | - Leo P Kouwenhoven
- Qutech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, 2600, GA, The Netherlands
- Microsoft Station Q Delft, Delft, 2600, GA, The Netherlands
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45
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Pan XH, Yang KJ, Chen L, Xu G, Liu CX, Liu X. Lattice-Symmetry-Assisted Second-Order Topological Superconductors and Majorana Patterns. PHYSICAL REVIEW LETTERS 2019; 123:156801. [PMID: 31702286 DOI: 10.1103/physrevlett.123.156801] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Indexed: 06/10/2023]
Abstract
We propose a realization of the lattice-symmetry-assisted second-order topological superconductors with corner Majorana zero modes (MZM) based on two-dimensional topological insulators (2DTI). The lattice symmetry can naturally lead to the anisotropic coupling of edge states along different directions to the in-plane magnetic field and conventional s-wave pairings, thus leading to a single MZM located at the corners for various lattice patterns. In particular, we focus on the 2DTI with D_{3d} lattice symmetry and found different types of gap opening for the edge states along the armchair and zigzag edges in a broad range of parameters. As a consequence, a single MZM exists at the corner between the zigzag and armchair edges, and is robust against weakly broken lattice symmetry. We propose to realize such corner MZMs in a variety of polygon patterns, such as triangles and quadrilaterals. We further show their potentials in building the Majorana network through constructing the Majorana Y junction under an in-plane magnetic field.
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Affiliation(s)
- Xiao-Hong Pan
- School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Kai-Jie Yang
- School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Department of Physics, the Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Li Chen
- School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Gang Xu
- School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Chao-Xing Liu
- Department of Physics, the Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Xin Liu
- School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
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46
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Ueda K, Matsuo S, Kamata H, Baba S, Sato Y, Takeshige Y, Li K, Jeppesen S, Samuelson L, Xu H, Tarucha S. Dominant nonlocal superconducting proximity effect due to electron-electron interaction in a ballistic double nanowire. SCIENCE ADVANCES 2019; 5:eaaw2194. [PMID: 31620554 PMCID: PMC6777966 DOI: 10.1126/sciadv.aaw2194] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 09/08/2019] [Indexed: 06/10/2023]
Abstract
Cooper pair splitting (CPS) can induce nonlocal correlation between two normal conductors that are coupled to a superconductor. CPS in a double one-dimensional electron gas is an appropriate platform for extracting a large number of entangled electron pairs and is one of the key ingredients for engineering Majorana fermions with no magnetic field. In this study, we investigated CPS by using a Josephson junction of a gate-tunable ballistic InAs double nanowire. The measured switching current into the two nanowires is significantly larger than the sum of the switching current into the respective nanowires, indicating that interwire superconductivity is dominant compared with intrawire superconductivity. From its dependence on the number of propagating channels in the nanowires, the observed CPS is assigned to one-dimensional electron-electron interaction. Our results will pave the way for the utilization of one-dimensional electron-electron interaction to reveal the physics of high-efficiency CPS and to engineer Majorana fermions in double nanowire systems via CPS.
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Affiliation(s)
- Kento Ueda
- Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Sadashige Matsuo
- Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
- Center for Emergent Matter Science, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- JST, PRESTO, 4-1-8 Honcho, Kawaguchi-shi, Saitama 332-0012, Japan
| | - Hiroshi Kamata
- Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
- Center for Emergent Matter Science, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - Shoji Baba
- Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Yosuke Sato
- Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Yuusuke Takeshige
- Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kan Li
- Beijing Key Laboratory of Quantum Devices, Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, China
| | - Sören Jeppesen
- Division of Solid State Physics, Lund University, Box 118, SE-221 00 Lund, Sweden
| | - Lars Samuelson
- Division of Solid State Physics, Lund University, Box 118, SE-221 00 Lund, Sweden
| | - Hongqi Xu
- Beijing Key Laboratory of Quantum Devices, Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, China
- Division of Solid State Physics, Lund University, Box 118, SE-221 00 Lund, Sweden
- Beijing Academy of Quantum Information Sciences, Beijing 100193, China
| | - Seigo Tarucha
- Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
- Center for Emergent Matter Science, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
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47
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Awoga OA, Cayao J, Black-Schaffer AM. Supercurrent Detection of Topologically Trivial Zero-Energy States in Nanowire Junctions. PHYSICAL REVIEW LETTERS 2019; 123:117001. [PMID: 31573272 DOI: 10.1103/physrevlett.123.117001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Indexed: 06/10/2023]
Abstract
We report the emergence of zero-energy states in the trivial phase of a short nanowire junction with a strong spin-orbit coupling and magnetic field, formed by strong coupling between the nanowire and two superconductors. The zero-energy states appear in the junction when the superconductors induce a large energy shift in the nanowire, such that the junction naturally forms a quantum dot, a process that is highly tunable by the superconductor width. Most importantly, we demonstrate that the zero-energy states produce a π shift in the phase-biased supercurrent, which can be used as a simple tool for their unambiguous detection, ruling out any Majorana-like interpretation.
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Affiliation(s)
- Oladunjoye A Awoga
- Department of Physics and Astronomy, Uppsala University, Box 516, S-751 20 Uppsala, Sweden
| | - Jorge Cayao
- Department of Physics and Astronomy, Uppsala University, Box 516, S-751 20 Uppsala, Sweden
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48
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Bjergfelt M, Carrad DJ, Kanne T, Aagesen M, Fiordaliso EM, Johnson E, Shojaei B, Palmstrøm CJ, Krogstrup P, Jespersen TS, Nygård J. Superconducting vanadium/indium-arsenide hybrid nanowires. NANOTECHNOLOGY 2019; 30:294005. [PMID: 30947145 DOI: 10.1088/1361-6528/ab15fc] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report MBE synthesis of InAs/vanadium hybrid nanowires. The vanadium was deposited without breaking ultra-high vacuum after InAs nanowire growth, minimizing any effect of oxidation and contamination at the interface between the two materials. We investigated four different substrate temperatures during vanadium deposition, ranging from -150 °C to 250 °C. The structural relation between vanadium and InAs depended on the deposition temperature. The three lower temperature depositions gave vanadium shells with a polycrystalline, granular morphology and the highest temperature resulted in vanadium reacting with the InAs nanowire. We fabricated electronic devices from the hybrid nanowires and obtained a high out-of-plane critical magnetic field, exceeding the bulk value for vanadium. However, size effects arising from the nanoscale grains resulted in the absence of a well-defined critical temperature, as well as device-to-device variation in the resistivity versus temperature dependence during the transition to the superconducting state.
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Affiliation(s)
- Martin Bjergfelt
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
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49
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Seidl J, Gluschke JG, Yuan X, Naureen S, Shahid N, Tan HH, Jagadish C, Micolich AP, Caroff P. Regaining a Spatial Dimension: Mechanically Transferrable Two-Dimensional InAs Nanofins Grown by Selective Area Epitaxy. NANO LETTERS 2019; 19:4666-4677. [PMID: 31241966 DOI: 10.1021/acs.nanolett.9b01703] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report a method for growing rectangular InAs nanofins with deterministic length, width, and height by dielectric-templated selective-area epitaxy. These freestanding nanofins can be transferred to lay flat on a separate substrate for device fabrication. A key goal was to regain a spatial dimension for device design compared to nanowires, while retaining the benefits of bottom-up epitaxial growth. The transferred nanofins were made into devices featuring multiple contacts for Hall effect and four-terminal resistance studies, as well as a global back-gate and nanoscale local top-gates for density control. Hall studies give a 3D electron density 2.5-5 × 1017 cm-3, corresponding to an approximate surface accumulation layer density 3-6 × 1012 cm-2 that agrees well with previous studies of InAs nanowires. We obtain Hall mobilities as high as 1200 cm2/(V s), field-effect mobilities as high as 4400 cm2/(V s), and clear quantum interference structure at temperatures as high as 20 K. Our devices show excellent prospects for fabrication into more complicated devices featuring multiple ohmic contacts, local gates, and possibly other functional elements, for example, patterned superconductor contacts, that may make them attractive options for future quantum information applications.
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Affiliation(s)
- J Seidl
- School of Physics , University of New South Wales , Sydney NSW 2052 , Australia
| | - J G Gluschke
- School of Physics , University of New South Wales , Sydney NSW 2052 , Australia
| | - X Yuan
- Department of Electronic Materials Engineering, Research School of Physics and Engineering , The Australian National University , Canberra ACT 2601 , Australia
- Hunan Key Laboratory for Supermicrostructure and Ultrafast Process, School of Physics and Electronics , Central South University , 932 South Lushan Road , Changsha , Hunan 410083 , P.R. China
| | - S Naureen
- Department of Electronic Materials Engineering, Research School of Physics and Engineering , The Australian National University , Canberra ACT 2601 , Australia
- IRnova AB , Electrum 236 , Kista SE-164 40 , Sweden
| | - N Shahid
- Department of Electronic Materials Engineering, Research School of Physics and Engineering , The Australian National University , Canberra ACT 2601 , Australia
- Finisar Sweden AB , Bruttovägen 7 , Järfälla SE-175 43 , Sweden
| | - H H Tan
- Department of Electronic Materials Engineering, Research School of Physics and Engineering , The Australian National University , Canberra ACT 2601 , Australia
| | - C Jagadish
- Department of Electronic Materials Engineering, Research School of Physics and Engineering , The Australian National University , Canberra ACT 2601 , Australia
| | - A P Micolich
- School of Physics , University of New South Wales , Sydney NSW 2052 , Australia
| | - P Caroff
- Department of Electronic Materials Engineering, Research School of Physics and Engineering , The Australian National University , Canberra ACT 2601 , Australia
- Microsoft Quantum Lab Delft , Delft University of Technology , 2600 GA Delft , The Netherlands
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50
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Val'kov VV, Kagan MY, Aksenov SV. Fano effect in Aharonov-Bohm ring with topologically superconducting bridge. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:225301. [PMID: 30818289 DOI: 10.1088/1361-648x/ab0b8c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Taking into account an inner structure of the arms of the Aharonov-Bohm ring (AB ring) we have analyzed the transport features related to the topological phase transition which is induced in a superconducting wire (SC wire) with strong spin-orbit interaction (SOI). The SC wire acts as a bridge connecting the arms. The in-plane magnetic-field dependence of linear-response conductance obtained using the nonequilibrium Green's functions in the tight-binding approximation revealed the Breit-Wigner and Fano resonances (FRs) if the wire is in the nontrivial phase. The effect is explained by the presence of two interacting transport channels in the system. As a result, the FRs are attributed to bound states in continuum (BSCs). The BSC lifetime is determined by both hopping parameters between subsystems and the SC-wire properties. It is established that the FR width and position are extremely sensitive to the type of the lowest-energy excitation in the SC wire, the Majorana or Andreev bound state (MBS or ABS, respectively). Moreover, it is shown that in the specific case of the AB ring, the T-shape geometry, the FR disappears for the transport via the MBS and the conductance is equal to one quantum. It doubles in the local transport regime. On the contrary, in the ABS case the local conductance vanishes. The influence of the mean-field Coulomb interactions and diagonal disorder in the SC wire on the FR is investigated.
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Affiliation(s)
- V V Val'kov
- Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Akademgorodok street 50/38, 660036 Krasnoyarsk, Russia
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