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Li R, Song W, Miao W, Yu Z, Wang Z, Yang S, Gao Y, Wang Y, Chen F, Geng Z, Yang L, Xu J, Feng X, Wang T, Zang Y, Li L, Shang R, Xue Q, He K, Zhang H. Selective-Area-Grown PbTe-Pb Planar Josephson Junctions for Quantum Devices. NANO LETTERS 2024; 24:4658-4664. [PMID: 38563608 DOI: 10.1021/acs.nanolett.4c00900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Planar Josephson junctions are predicted to host Majorana zero modes. The material platforms in previous studies are two-dimensional electron gases (InAs, InSb, InAsSb, and HgTe) coupled to a superconductor such as Al or Nb. Here, we introduce a new material platform for planar JJs, the PbTe-Pb hybrid. The semiconductor, PbTe, was grown as a thin film via selective area epitaxy. The Josephson junction was defined by a shadow wall during the deposition of superconductor Pb. Scanning transmission electron microscopy reveals a sharp semiconductor-superconductor interface. Gate-tunable supercurrents and multiple Andreev reflections are observed. A perpendicular magnetic field causes interference patterns of the switching current, exhibiting Fraunhofer-like and SQUID-like behaviors. We further demonstrate a prototype device for Majorana detection wherein phase bias and tunneling spectroscopy are applicable.
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Affiliation(s)
- Ruidong Li
- 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
| | - Wentao Miao
- 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
| | - Zhaoyu Wang
- 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
| | - Yichun Gao
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - 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
| | - Zuhan Geng
- 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
| | - Jiaye Xu
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, 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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Vacancy-engineered nodal-line semimetals. Sci Rep 2022; 12:14981. [PMID: 36056065 DOI: 10.1038/s41598-022-18519-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 08/09/2022] [Indexed: 11/08/2022] Open
Abstract
Symmetry-enforced nodal-line semimetals are immune to perturbations that preserve the underlying symmetries. This intrinsic robustness enables investigations of fundamental phenomena and applications utilizing diverse materials design techniques. The drawback of symmetry-enforced nodal-line semimetals is that the crossings of energy bands are constrained to symmetry-invariant momenta in the Brillouin zone. On the other end are accidental nodal-line semimetals whose band crossings, not being enforced by symmetry, are easily destroyed by perturbations. Some accidental nodal-line semimetals have, however, the advantage that their band crossings can occur in generic locations in the Brillouin zone, and thus can be repositioned to tailor material properties. We show that lattice engineering with periodic distributions of vacancies yields a hybrid type of nodal-line semimetals which possess symmetry-enforced nodal lines and accidental nodal lines, with the latter endowed with an enhanced robustness to perturbations. Both types of nodal lines are explained by a symmetry analysis of an effective model which captures the relevant characteristics of the proposed materials, and are verified by first-principles calculations of vacancy-engineered borophene polymorphs. Our findings offer an alternative path to relying on complicated compounds to design robust nodal-line semimetals; one can instead remove atoms from a common monoatomic material.
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Elfeky BH, Lotfizadeh N, Schiela WF, Strickland WM, Dartiailh M, Sardashti K, Hatefipour M, Yu P, Pankratova N, Lee H, Manucharyan VE, Shabani J. Local Control of Supercurrent Density in Epitaxial Planar Josephson Junctions. NANO LETTERS 2021; 21:8274-8280. [PMID: 34570504 DOI: 10.1021/acs.nanolett.1c02771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The critical current response to an applied out-of-plane magnetic field in a Josephson junction provides insight into the uniformity of its current distribution. In Josephson junctions with semiconducting weak links, the carrier density, and therefore the overall current distribution, can be modified electrostatically via metallic gates. Here, we show local control of the current distribution in an epitaxial Al-InAs Josephson junction equipped with five minigates. We demonstrate that not only can the junction width be electrostatically defined but also the current profile can be locally adjusted to form superconducting quantum interference devices. Our studies show enhanced edge conduction in such long junctions, which can be eliminated by minigates to create a uniform current distribution.
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Affiliation(s)
- Bassel Heiba Elfeky
- Department of Physics, New York University, New York, New York 10003, United States
| | - Neda Lotfizadeh
- Department of Physics, New York University, New York, New York 10003, United States
| | - William F Schiela
- Department of Physics, New York University, New York, New York 10003, United States
| | - William M Strickland
- Department of Physics, New York University, New York, New York 10003, United States
| | - Matthieu Dartiailh
- Department of Physics, New York University, New York, New York 10003, United States
| | - Kasra Sardashti
- Department of Physics, New York University, New York, New York 10003, United States
| | - Mehdi Hatefipour
- Department of Physics, New York University, New York, New York 10003, United States
| | - Peng Yu
- Department of Physics, New York University, New York, New York 10003, United States
| | - Natalia Pankratova
- Department of Physics, Joint Quantum Institute, and Quantum Materials Center, University of Maryland, College Park, Maryland 20742, United States
| | - Hanho Lee
- Department of Physics, Joint Quantum Institute, and Quantum Materials Center, University of Maryland, College Park, Maryland 20742, United States
| | - Vladimir E Manucharyan
- Department of Physics, Joint Quantum Institute, and Quantum Materials Center, University of Maryland, College Park, Maryland 20742, United States
| | - Javad Shabani
- Department of Physics, New York University, New York, New York 10003, United States
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