1
|
Ding C, Lu Q, Shao D, Zhang Z, Han Y, Wang J, Sun J. Two-Dimensional M-Chalcogene Family with Tunable Superconducting, Topological, and Magnetic Properties. NANO LETTERS 2024; 24:9953-9960. [PMID: 39102284 DOI: 10.1021/acs.nanolett.4c02508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/06/2024]
Abstract
An interesting question is whether chalcogen atoms can emulate the role of carbon or boron elements stabilized between two transition metal layers, as observed in MXenes or MBenes. Here, we predict a new family of two-dimensional ternary compounds M4XY2 (where M = Pd, Y, Zr, etc.; X = S, Se, Te; and Y = Cl, Br, I), named M-chalcogene. Through first-principles calculations, we reveal diverse physical properties in these compounds, including superconducting, topological, and magnetic characteristics, where the bilayer transition metals play crucial roles. Moreover, the expected helical edge states and superconducting transition temperatures in Pd4SCl2 can be finely tuned by strains. Additionally, the Ti4SCl2 is predicted to be a topological insulator and shows promise as a gas sensor candidate for certain exotic gases. Our findings expand two-dimensional material families and provide promising platforms for diverse physical phenomena with efficient tunability by external stimuli for various applications.
Collapse
Affiliation(s)
- Chi Ding
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Qing Lu
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Dexi Shao
- School of Physics, Hangzhou Normal University, Hangzhou 311121, China
| | - Zhongwei Zhang
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Yu Han
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Junjie Wang
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Jian Sun
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| |
Collapse
|
2
|
Li P, Zhang J, Zhu D, Chen CQ, Yi E, Shen B, Hou Y, Yan Z, Yao DX, Guo D, Zhong D. Observation of In-Gap States in a Two-Dimensional CrI 2/NbSe 2 Heterostructure. NANO LETTERS 2024; 24:9468-9476. [PMID: 39047142 DOI: 10.1021/acs.nanolett.4c01848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
Low-dimensional magnetic structures coupled with superconductors are promising platforms for realizing Majorana zero modes, which have potential applications in topological quantum computing. Here, we report a two-dimensional (2D) magnetic-superconducting heterostructure consisting of single-layer chromium diiodide (CrI2) on a niobium diselenide (NbSe2) superconductor. Single-layer CrI2 nanosheets, which hold antiferromagnetic (AFM) ground states by our first-principles calculations, were epitaxially grown on the layered NbSe2 substrate. Using scanning tunneling microscopy/spectroscopy, we observed robust in-gap states spatially located at the edge of the nanosheets and defect-induced zero-energy peaks inside the CrI2 nanosheets. Magnetic-flux vortices induced by an external field exhibit broken 3-fold rotational symmetry of the pristine NbSe2 superconductor, implying the efficient modulation of the interfacial superconducting states by the epitaxial CrI2 layer. A phenomenological model suggests the existence of chiral edge states in a 2D AFM-superconducting hybrid system with an even Chern number, providing a qualitatively plausible understanding for our experimental observation.
Collapse
Affiliation(s)
- Peigen Li
- School of Physics & Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Sun Yat-sen University, 510275 Guangzhou, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, 510275 Guangzhou, China
| | - Jihai Zhang
- School of Physics & Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Sun Yat-sen University, 510275 Guangzhou, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, 510275 Guangzhou, China
| | - Di Zhu
- School of Physics & Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Sun Yat-sen University, 510275 Guangzhou, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, 510275 Guangzhou, China
| | - Cui-Qun Chen
- School of Physics & Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Sun Yat-sen University, 510275 Guangzhou, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, 510275 Guangzhou, China
| | - Enkui Yi
- School of Physics & Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Sun Yat-sen University, 510275 Guangzhou, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, 510275 Guangzhou, China
| | - Bing Shen
- School of Physics & Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Sun Yat-sen University, 510275 Guangzhou, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, 510275 Guangzhou, China
| | - Yusheng Hou
- School of Physics & Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Sun Yat-sen University, 510275 Guangzhou, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, 510275 Guangzhou, China
| | - Zhongbo Yan
- School of Physics & Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Sun Yat-sen University, 510275 Guangzhou, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, 510275 Guangzhou, China
| | - Dao-Xin Yao
- School of Physics & Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Sun Yat-sen University, 510275 Guangzhou, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, 510275 Guangzhou, China
| | - Donghui Guo
- School of Physics & Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Sun Yat-sen University, 510275 Guangzhou, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, 510275 Guangzhou, China
| | - Dingyong Zhong
- School of Physics & Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, Sun Yat-sen University, 510275 Guangzhou, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, 510275 Guangzhou, China
| |
Collapse
|
3
|
Majek P, Weymann I. Spin-selective transport in a correlated double quantum dot-Majorana wire system. Sci Rep 2024; 14:17762. [PMID: 39085311 PMCID: PMC11291930 DOI: 10.1038/s41598-024-66478-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 07/01/2024] [Indexed: 08/02/2024] Open
Abstract
In this work we investigate the spin-dependent transport through a double quantum dot embedded in a ferromagnetic tunnel junction and side attached to a topological superconducting nanowire hosting Majorana zero-energy modes. We focus on the transport regime when the Majorana mode leaks into the double quantum dot competing with the two-stage Kondo effect and the ferromagnetic-contact-induced exchange field. In particular, we determine the system's spectral properties and analyze the temperature dependence of the spin-resolved linear conductance by means of the numerical renormalization group method. Our study reveals unique signatures of the interplay between the spin-resolved tunneling, the Kondo effect and the Majorana modes, which are visible in the transport characteristics. In particular, we uncover a competing character of the coupling to topological superconductor and that to ferromagnetic leads, which can be observed already for very low spin polarization of the electrodes. This is signaled by an almost complete quenching of the conductance in one of the spin channels which is revealed through perfect conductance spin polarization. Moreover, we show that the conductance spin polarization can change sign depending on the magnitude of spin imbalance in the leads and strength of interaction with topological wire. Thus, our work demonstrates that even minuscule spin polarization of tunneling processes can have large impact on the transport properties of the system.
Collapse
Affiliation(s)
- Piotr Majek
- Institute of Spintronics and Quantum Information, Faculty of Physics, Adam Mickiewicz University, ul. Uniwersytetu Poznańskiego 2, 61-614, Poznań, Poland.
| | - Ireneusz Weymann
- Institute of Spintronics and Quantum Information, Faculty of Physics, Adam Mickiewicz University, ul. Uniwersytetu Poznańskiego 2, 61-614, Poznań, Poland
| |
Collapse
|
4
|
Hsu CH. Interaction- and phonon-induced topological phase transitions in double helical liquids. NANOSCALE HORIZONS 2024. [PMID: 39049706 DOI: 10.1039/d4nh00254g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
Helical liquids, formed by time-reversal pairs of interacting electrons in topological edge channels, provide a platform for stabilizing topological superconductivity upon introducing local and nonlocal pairings through the proximity effect. Here, we investigate the effects of electron-electron interactions and phonons on the topological superconductivity in two parallel channels of such helical liquids. Interactions between electrons in different channels tend to reduce nonlocal pairing, suppressing the topological regime. Additionally, electron-phonon coupling breaks the self duality in the electronic subsystem and renormalizes the pairing strengths. Notably, while earlier perturbative calculations suggested that longitudinal phonons have no effect on helical liquids themselves to the leading order, our nonperturbative analysis shows that phonons can induce transitions between topological and trivial superconductivity, thereby weakening the stability of topological zero modes. Our findings highlight practical limitations in realizing topological zero modes in various systems hosting helical channels, including quantum spin Hall insulators, higher-order topological insulators, and their fractional counterparts recently observed in twisted bilayer systems.
Collapse
Affiliation(s)
- Chen-Hsuan Hsu
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan.
| |
Collapse
|
5
|
Ning Z, Qian J, Liu Y, Chen F, Zhang M, Deng L, Yuan X, Ge Q, Jin H, Zhang G, Peng W, Qiao S, Mu G, Chen Y, Li W. Coexistence of Ferromagnetism and Superconductivity at KTaO 3 Heterointerfaces. NANO LETTERS 2024; 24:7134-7141. [PMID: 38828962 DOI: 10.1021/acs.nanolett.4c02500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
The coexistence of superconductivity and ferromagnetism is a long-standing issue in superconductivity due to the antagonistic nature of these two ordered states. Experimentally identifying and characterizing novel heterointerface superconductors that coexist with magnetism presents significant challenges. Here, we report the observation of two-dimensional long-range ferromagnetic order in a KTaO3 heterointerface superconductor, showing the coexistence of superconductivity and ferromagnetism. Remarkably, our direct current superconducting quantum interference device measurements reveal an in-plane magnetization hysteresis loop persisting above room temperature. Moreover, first-principles calculations and X-ray magnetic circular dichroism measurements provide decisive insights into the origin of the observed robust ferromagnetism, attributing it to oxygen vacancies that localize electrons in nearby Ta 5d states. Our findings suggest KTaO3 heterointerfaces as time-reversal symmetry breaking superconductors, injecting fresh momentum into the exploration of the intricate interplay between superconductivity and magnetism enhanced by the strong spin-orbit coupling inherent to the heavy Ta in 5d orbitals.
Collapse
Affiliation(s)
- Zhongfeng Ning
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Jiahui Qian
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Yixin Liu
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fan Chen
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mingzhu Zhang
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liwei Deng
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xinli Yuan
- Thermo Fisher Scientific China, Shanghai 201203, China
| | - Qingqin Ge
- Thermo Fisher Scientific China, Shanghai 201203, China
| | - Hua Jin
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Guanqun Zhang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Wei Peng
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shan Qiao
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gang Mu
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Chen
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Wei Li
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| |
Collapse
|
6
|
Niu C, Wang M, Zhang Z, Qiu G, Wang Y, Zheng D, Liao PY, Wu W, Ye PD. Superconducting Field-Effect Transistors with Pd xTe-Te Intimate Contacts. ACS NANO 2024; 18:15107-15113. [PMID: 38819119 DOI: 10.1021/acsnano.4c02352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
Superconducting-based electronic devices have shown great potential for future quantum computing applications. One key building block device is a superconducting field-effect transistor based on a superconductor-semiconductor-superconductor Josephson-junction (JJ) with a gate-tunable semiconducting channel. However, the performance of such devices is highly dependent on the quality of the superconductor to semiconductor interface. In this study, we present an alternative method to obtain a high-quality interface by using intimate contact. We investigate the proximity-induced superconductivity in chiral crystal tellurium (Te) and fabricate a PdxTe-Te-PdxTe JJ with an ambipolar supercurrent that is gate-tunable and exhibits multiple Andreev reflections. The semiconducting two-dimensional Te single crystal is grown hydrothermally and partially converted to superconducting PdxTe by controlled annealing. Our work demonstrates a promising path for realizing controllable superconducting electronic devices with high-quality superconducting interfaces; thus, we can continue to advance the field of quantum computing and other interface-based technologies.
Collapse
Affiliation(s)
- Chang Niu
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Mingyi Wang
- School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Zhuocheng Zhang
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Gang Qiu
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Yixiu Wang
- School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Dongqi Zheng
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Pai-Ying Liao
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Wenzhuo Wu
- School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Peide D Ye
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
| |
Collapse
|
7
|
Almoalem A, Feldman I, Mangel I, Shlafman M, Yaish YE, Fischer MH, Moshe M, Ruhman J, Kanigel A. The observation of π-shifts in the Little-Parks effect in 4Hb-TaS 2. Nat Commun 2024; 15:4623. [PMID: 38816364 PMCID: PMC11139670 DOI: 10.1038/s41467-024-48260-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 04/23/2024] [Indexed: 06/01/2024] Open
Abstract
Finding evidence of non-trivial pairing states is one of the greatest experimental challenges in the field of unconventional superconductivity. Such evidence requires phase-sensitive probes susceptible to the internal structure of the order parameter. We report the measurement of the Little-Parks effect in the unconventional superconductor candidate 4Hb-TaS2. In half of our rings, which are fabricated from single-crystals, we find a π-shift in the transition-temperature oscillations. According to theory, such a π-shift is only possible if the order parameter is non-s-wave. In the absence of crystallographic defects, the shift provides evidence of a multi-component order parameter. Thus, this observation increases the likelihood of the two-component order parameter scenario in 4Hb-TaS2. Furthermore, we show that Tc is enhanced as a function of the out-of-plane field when a constant in-plane field is applied, which we explain using a two-component order-parameter.
Collapse
Affiliation(s)
- Avior Almoalem
- Physics Department, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Irena Feldman
- Physics Department, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Ilay Mangel
- Physics Department, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Michael Shlafman
- Andrew and Erna Viterbi Faculty of Electrical and Computer Engineering, Technion, Haifa, 32000, Israel
| | - Yuval E Yaish
- Andrew and Erna Viterbi Faculty of Electrical and Computer Engineering, Technion, Haifa, 32000, Israel
| | - Mark H Fischer
- Department of Physics, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Michael Moshe
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Jonathan Ruhman
- Department of Physics, Bar-Ilan University, 52900, Ramat Gan, Israel
| | - Amit Kanigel
- Physics Department, Technion-Israel Institute of Technology, Haifa, 32000, Israel.
| |
Collapse
|
8
|
Hirayama M, Nomoto T, Arita R. Topological band inversion and chiral Majorana mode in hcp thallium. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:275502. [PMID: 38447148 DOI: 10.1088/1361-648x/ad3093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 03/06/2024] [Indexed: 03/08/2024]
Abstract
The chiral Majorana fermion is an exotic particle that is its own antiparticle. It can arise in a one-dimensional edge of topological materials, and especially that in a topological superconductor can be exploited in non-Abelian quantum computation. While the chiral Majorana mode (CMM) remains elusive, a promising situation is realized when superconductivity coexists with a topologically non-trivial surface state. Here, we perform fully non-empirical calculation for the CMM considering superconductivity and surface relaxation, and show that hexagonal close-packed thallium (Tl) has an ideal electronic state that harbors the CMM. Thekz=0plane of Tl is a mirror plane, realizing a full-gap band inversion corresponding to a topological crystalline insulating phase. Its surface and hinge are stable and easy to make various structures. Another notable feature is that the surface Dirac point is very close to the Fermi level, so that a small Zeeman field can induce a topological transition. Our calculation indicates that Tl will provide a new platform of the Majorana fermion.
Collapse
Affiliation(s)
- Motoaki Hirayama
- Quantum-Phase Electronics Center, University of Tokyo, Tokyo 113-8656, Japan
- RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako 351-0198, Japan
| | - Takuya Nomoto
- Research Center for Advanced Science and Technology, University of Tokyo, Tokyo 153-8904, Japan
| | - Ryotaro Arita
- RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako 351-0198, Japan
- Research Center for Advanced Science and Technology, University of Tokyo, Tokyo 153-8904, Japan
| |
Collapse
|
9
|
Wrześniewski K, Weymann I. Cross-correlations between currents and tunnel magnetoresistance in interacting double quantum dot-Majorana wire system. Sci Rep 2024; 14:7815. [PMID: 38570697 PMCID: PMC10991420 DOI: 10.1038/s41598-024-58344-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 03/27/2024] [Indexed: 04/05/2024] Open
Abstract
We theoretically investigate the spin and charge transport properties of a double quantum dot coupled to distinct edges of the nanowire hosting Majorana zero-energy modes. The focus is on the analysis of the currents flowing through the left and right junctions and their cross-correlations. We show that the system reveals very different transport properties depending on the detuning protocol of the quantum dot energy levels. For the symmetric detuning, the current dependencies reveal only two maxima associated with resonant tunneling, and currents in the left and right arms of the system reveal weak positive cross-correlations. On the other hand, for antisymmetric detuning, the flow of electrons into drains is maximized and strongly correlated in one bias voltage direction, while for the opposite bias direction a spin blockade is predicted. Furthermore, we observe a suppression of the current cross-correlations at a highly symmetric detuning point, indicating the involvement of the Majorana zero-energy modes in the transport processes. To gain insight into the role of the spin polarization of the Majorana edge states, we analyze the spin-dependent transport characteristics by considering the relationship between the spin canting angle, which describes the coupling of the Majorana modes to the spin of the quantum dots, and the magnetic configurations of the ferromagnetic drains. Moreover, we examine the non-local zero bias anomaly in the differential conductance, detailed analysis of which revealed a specific operational mode of the device that can facilitate the identification of the Majorana presence in the quantum dot-Majorana wire system. Finally, we also consider the transport properties in different magnetic configurations of the system and discuss the behavior of the associated tunnel magnetoresistance.
Collapse
Affiliation(s)
- Kacper Wrześniewski
- Faculty of Physics, Institute of Spintronics and Quantum Information, Adam Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614, Poznan, Poland.
| | - Ireneusz Weymann
- Faculty of Physics, Institute of Spintronics and Quantum Information, Adam Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614, Poznan, Poland
| |
Collapse
|
10
|
Barrier J, Kim M, Kumar RK, Xin N, Kumaravadivel P, Hague L, Nguyen E, Berdyugin AI, Moulsdale C, Enaldiev VV, Prance JR, Koppens FHL, Gorbachev RV, Watanabe K, Taniguchi T, Glazman LI, Grigorieva IV, Fal'ko VI, Geim AK. One-dimensional proximity superconductivity in the quantum Hall regime. Nature 2024; 628:741-745. [PMID: 38658686 DOI: 10.1038/s41586-024-07271-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 03/05/2024] [Indexed: 04/26/2024]
Abstract
Extensive efforts have been undertaken to combine superconductivity and the quantum Hall effect so that Cooper-pair transport between superconducting electrodes in Josephson junctions is mediated by one-dimensional edge states1-6. This interest has been motivated by prospects of finding new physics, including topologically protected quasiparticles7-9, but also extends into metrology and device applications10-13. So far it has proven challenging to achieve detectable supercurrents through quantum Hall conductors2,3,6. Here we show that domain walls in minimally twisted bilayer graphene14-18 support exceptionally robust proximity superconductivity in the quantum Hall regime, allowing Josephson junctions to operate in fields close to the upper critical field of superconducting electrodes. The critical current is found to be non-oscillatory and practically unchanging over the entire range of quantizing fields, with its value being limited by the quantum conductance of ballistic, strictly one-dimensional, electronic channels residing within the domain walls. The system described is unique in its ability to support Andreev bound states at quantizing fields and offers many interesting directions for further exploration.
Collapse
Affiliation(s)
- Julien Barrier
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- National Graphene Institute, University of Manchester, Manchester, UK.
| | - Minsoo Kim
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- Department of Applied Physics, Kyung Hee University, Yong-in, South Korea
| | - Roshan Krishna Kumar
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - Na Xin
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- Department of Chemistry, Zhejiang University, Hangzhou, China.
| | - P Kumaravadivel
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Lee Hague
- National Graphene Institute, University of Manchester, Manchester, UK
| | - E Nguyen
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - A I Berdyugin
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Christian Moulsdale
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - V V Enaldiev
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - J R Prance
- Department of Physics, Lancaster University, Lancaster, UK
| | - F H L Koppens
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain
| | - R V Gorbachev
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - K Watanabe
- National Institute for Materials Science, Tsukuba, Japan
| | - T Taniguchi
- National Institute for Materials Science, Tsukuba, Japan
| | - L I Glazman
- Department of Physics, Yale University, New Haven, CT, USA
| | - I V Grigorieva
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
| | - V I Fal'ko
- Department of Physics and Astronomy, University of Manchester, Manchester, UK
- National Graphene Institute, University of Manchester, Manchester, UK
- Henry Royce Institute for Advanced Materials, University of Manchester, Manchester, UK
| | - A K Geim
- Department of Physics and Astronomy, University of Manchester, Manchester, UK.
- National Graphene Institute, University of Manchester, Manchester, UK.
| |
Collapse
|
11
|
Kao WH, Perkins NB, Halász GB. Vacancy Spectroscopy of Non-Abelian Kitaev Spin Liquids. PHYSICAL REVIEW LETTERS 2024; 132:136503. [PMID: 38613268 DOI: 10.1103/physrevlett.132.136503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 02/16/2024] [Indexed: 04/14/2024]
Abstract
Spin vacancies in the non-Abelian Kitaev spin liquid are known to harbor Majorana zero modes, potentially enabling topological quantum computing at elevated temperatures. Here, we study the spectroscopic signatures of such Majorana zero modes in a scanning tunneling setup where a non-Abelian Kitaev spin liquid with a finite density of spin vacancies forms a tunneling barrier between a tip and a substrate. Our key result is a well-defined peak close to zero bias voltage in the derivative of the tunneling conductance whose voltage and intensity both increase with the density of vacancies. This "quasi-zero-voltage peak" is identified as the closest analog of the zero-voltage peak observed in topological superconductors that additionally reflects the fractionalized nature of spin-liquid-based Majorana zero modes. We further highlight a single-fermion Van Hove singularity at a higher voltage that reveals the energy scale of the emergent Majorana fermions in the Kitaev spin liquid. Our proposed signatures are within reach of current experiments on the candidate material α-RuCl_{3}.
Collapse
Affiliation(s)
- Wen-Han Kao
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Natalia B Perkins
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Gábor B Halász
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Quantum Science Center, Oak Ridge, Tennessee 37831, USA
| |
Collapse
|
12
|
Ji X, Yang X. Generalized bulk-boundary correspondence in periodically driven non-Hermitian systems. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:243001. [PMID: 38387101 DOI: 10.1088/1361-648x/ad2c73] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 02/22/2024] [Indexed: 02/24/2024]
Abstract
We present a pedagogical review of the periodically driven non-Hermitian systems, particularly on the rich interplay between the non-Hermitian skin effect and the topology. We start by reviewing the non-Bloch band theory of the static non-Hermitian systems and discuss the establishment of its generalized bulk-boundary correspondence (BBC). Ultimately, we focus on the non-Bloch band theory of two typical periodically driven non-Hermitian systems: harmonically driven non-Hermitian system and periodically quenched non-Hermitian system. The non-Bloch topological invariants were defined on the generalized Brillouin zone and the real space wave functions to characterize the Floquet non-Hermtian topological phases. Then, the generalized BBC was established for the two typical periodically driven non-Hermitian systems. Additionally, we review novel phenomena in the higher-dimensional periodically driven non-Hermitian systems, including Floquet non-Hermitian higher-order topological phases and Floquet hybrid skin-topological modes. The experimental realizations and recent advances have also been surveyed. Finally, we end with a summarization and hope this pedagogical review can motivate further research on Floquet non-Hermtian topological physics.
Collapse
Affiliation(s)
- Xiang Ji
- Department of Physics, Jiangsu University, Zhenjiang 212013, People's Republic of China
| | - Xiaosen Yang
- Department of Physics, Jiangsu University, Zhenjiang 212013, People's Republic of China
| |
Collapse
|
13
|
Hu LH, Zhang RX. Dislocation Majorana bound states in iron-based superconductors. Nat Commun 2024; 15:2337. [PMID: 38491015 PMCID: PMC10943028 DOI: 10.1038/s41467-024-46618-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 03/04/2024] [Indexed: 03/18/2024] Open
Abstract
We show that lattice dislocations of topological iron-based superconductors such as FeTe1-xSex will intrinsically trap non-Abelian Majorana quasiparticles, in the absence of any external magnetic field. Our theory is motivated by the recent experimental observations of normal-state weak topology and surface magnetism that coexist with superconductivity in FeTe1-xSex, the combination of which naturally achieves an emergent second-order topological superconductivity in a two-dimensional subsystem spanned by screw or edge dislocations. This exemplifies a new embedded higher-order topological phase in class D, where Majorana zero modes appear around the "corners" of a low-dimensional embedded subsystem, instead of those of the full crystal. A nested domain wall theory is developed to understand the origin of these defect Majorana zero modes. When the surface magnetism is absent, we further find that s± pairing symmetry itself is capable of inducing a different type of class-DIII embedded higher-order topology with defect-bound Majorana Kramers pairs. We also provide detailed discussions on the real-world material candidates for our proposals, including FeTe1-xSex, LiFeAs, β-PdBi2, and heterostructures of bismuth, etc. Our work establishes lattice defects as a new venue to achieve high-temperature topological quantum information processing.
Collapse
Affiliation(s)
- Lun-Hui Hu
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, TN, USA
- Institute for Advanced Materials and Manufacturing, The University of Tennessee, Knoxville, TN, USA
- Center for Correlated Matter and School of Physics, Zhejiang University, Hangzhou, China
| | - Rui-Xing Zhang
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, TN, USA.
- Institute for Advanced Materials and Manufacturing, The University of Tennessee, Knoxville, TN, USA.
- Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN, USA.
| |
Collapse
|
14
|
Gassner S, Weber CS, Claassen M. Light-induced switching between singlet and triplet superconducting states. Nat Commun 2024; 15:1776. [PMID: 38413590 PMCID: PMC10899631 DOI: 10.1038/s41467-024-45949-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 02/08/2024] [Indexed: 02/29/2024] Open
Abstract
While the search for topological triplet-pairing superconductivity has remained a challenge, recent developments in optically stabilizing metastable superconducting states suggest a new route to realizing this elusive phase. Here, we devise a testable theory of competing superconducting orders that permits ultrafast switching to an opposite-parity superconducting phase in centrosymmetric crystals with strong spin-orbit coupling. Using both microscopic and phenomenological models, we show that dynamical inversion symmetry breaking with a tailored light pulse can induce odd-parity (spin triplet) order parameter oscillations in a conventional even-parity (spin singlet) superconductor, which when driven strongly can send the system to a competing minimum in its free energy landscape. Our results provide new guiding principles for engineering unconventional electronic phases using light, suggesting a fundamentally non-equilibrium route toward realizing topological superconductivity.
Collapse
Affiliation(s)
- Steven Gassner
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Clara S Weber
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Institut für Theorie der Statistischen Physik, RWTH Aachen and JARA - Fundamentals of Future Information Technology, D-52056, Aachen, Germany
| | - Martin Claassen
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| |
Collapse
|
15
|
Riberolles SXM, Slade TJ, Han T, Li B, Abernathy DL, Canfield PC, Ueland BG, Orth PP, Ke L, McQueeney RJ. Chiral and flat-band magnetic quasiparticles in ferromagnetic and metallic kagome layers. Nat Commun 2024; 15:1592. [PMID: 38383472 PMCID: PMC10882050 DOI: 10.1038/s41467-024-45841-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 02/02/2024] [Indexed: 02/23/2024] Open
Abstract
Magnetic kagome metals are a promising platform to develop unique quantum transport and optical phenomena caused by the interplay between topological electronic bands, strong correlations, and magnetic order. This interplay may result in exotic quasiparticles that describe the coupled electronic and spin excitations on the frustrated kagome lattice. Here, we observe novel elementary magnetic excitations within the ferromagnetic Mn kagome layers in TbMn6Sn6 using inelastic neutron scattering. We observe sharp, collective acoustic magnons and identify flat-band magnons that are localized to a hexagonal plaquette due to the special geometry of the kagome layer. Surprisingly, we observe another type of elementary magnetic excitation; a chiral magnetic quasiparticle that is also localized on a hexagonal plaquette. The short lifetime of localized flat-band and chiral quasiparticles suggest that they are hybrid excitations that decay into electronic states.
Collapse
Affiliation(s)
| | | | - Tianxiong Han
- Ames National Laboratory, Ames, IA, 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - Bing Li
- Ames National Laboratory, Ames, IA, 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - D L Abernathy
- Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - P C Canfield
- Ames National Laboratory, Ames, IA, 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - B G Ueland
- Ames National Laboratory, Ames, IA, 50011, USA
| | - P P Orth
- Ames National Laboratory, Ames, IA, 50011, USA
- Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA
| | - Liqin Ke
- Ames National Laboratory, Ames, IA, 50011, USA
| | - R J McQueeney
- Ames National Laboratory, Ames, IA, 50011, USA.
- Department of Physics and Astronomy, Iowa State University, Ames, IA, 50011, USA.
| |
Collapse
|
16
|
Xu X, Li Y, Chien CL. Observation of Odd-Parity Superconductivity with the Geshkenbein-Larkin-Barone Composite Rings. PHYSICAL REVIEW LETTERS 2024; 132:056001. [PMID: 38364125 DOI: 10.1103/physrevlett.132.056001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 11/25/2023] [Accepted: 12/19/2023] [Indexed: 02/18/2024]
Abstract
Phase-sensitive measurements on a composite ring made of a superconductor of interest connected by a known singlet s-wave superconductor can unambiguously determine its pairing symmetry. In composite rings with epitaxial β-Bi_{2}Pd and s-wave Nb, we have observed half-integer-quantum flux when Nb is connected to the opposite crystalline ends of β-Bi_{2}Pd and integer-quantum flux when Nb is connected to the same crystalline ends of β-Bi_{2}Pd. With ascending temperature, the half-integer-flux quantization transits to integer-flux quantization, before the eventual loss of phase coherence. These findings point to odd-parity pairing symmetry in superconducting β-Bi_{2}Pd.
Collapse
Affiliation(s)
- Xiaoying Xu
- William H. Miller III Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Yufan Li
- William H. Miller III Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - C L Chien
- William H. Miller III Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| |
Collapse
|
17
|
Clericò V, Wójcik P, Vezzosi A, Rocci M, Demontis V, Zannier V, Díaz-Fernández Á, Díaz E, Bellani V, Domínguez-Adame F, Diez E, Sorba L, Bertoni A, Goldoni G, Rossella F. Spin-Resolved Magneto-Tunneling and Giant Anisotropic g-Factor in Broken Gap InAs-GaSb Core-Shell Nanowires. NANO LETTERS 2024; 24:790-796. [PMID: 38189790 PMCID: PMC10811674 DOI: 10.1021/acs.nanolett.3c02559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 12/20/2023] [Accepted: 12/26/2023] [Indexed: 01/09/2024]
Abstract
We experimentally and computationally investigate the magneto-conductance across the radial heterojunction of InAs-GaSb core-shell nanowires under a magnetic field, B, up to 30 T and at temperatures in the range 4.2-200 K. The observed double-peak negative differential conductance markedly blue-shifts with increasing B. The doublet accounts for spin-polarized currents through the Zeeman split channels of the InAs (GaSb) conduction (valence) band and exhibits strong anisotropy with respect to B orientation and marked temperature dependence. Envelope function approximation and a semiclassical (WKB) approach allow to compute the magnetic quantum states of InAs and GaSb sections of the nanowire and to estimate the B-dependent tunneling current across the broken-gap interface. Disentangling different magneto-transport channels and a thermally activated valence-to-valence band transport current, we extract the g-factor from the spin-up and spin-down dI/dV branch dispersion, revealing a giant, strongly anisotropic g-factor in excess of 60 (100) for the radial (tilted) field configurations.
Collapse
Affiliation(s)
- Vito Clericò
- Nanolab-Nanotechnology
Group, Departamento de Física Fundamental, Universidad de Salamanca, Plaza de la Merced, s/n., 37008-Salamanca, Spain
| | - Pawel Wójcik
- AGH
University of Krakow, Faculty of Physics and Applied Computer Science, Al. Mickiewicza 30, 30-059 Krakow, Poland
| | - Andrea Vezzosi
- Dipartimento
di Scienze Fisiche, Informatiche e Matematiche, Università di Modena e Reggio Emilia, Via Campi 213/a, I-41125 Modena, Italy
| | - Mirko Rocci
- NEST,
Scuola Normale Superiore e Istituto di Nanoscienze-CNR, Piazza san Silvestro 12, I-56127 Pisa, Italy
| | - Valeria Demontis
- NEST,
Scuola Normale Superiore e Istituto di Nanoscienze-CNR, Piazza san Silvestro 12, I-56127 Pisa, Italy
- Department
of Physics, University of Cagliari, S.P. Monserrato-Sestu, Monserrato, 09042, Italy
| | - Valentina Zannier
- NEST,
Scuola Normale Superiore e Istituto di Nanoscienze-CNR, Piazza san Silvestro 12, I-56127 Pisa, Italy
| | - Álvaro Díaz-Fernández
- GISC, Departamento
de Física de Materiales, Universidad
Complutense de Madrid, Avenida Complutense, s/n, Ciudad Universitaria, 28040 Madrid, Spain
| | - Elena Díaz
- GISC, Departamento
de Física de Materiales, Universidad
Complutense de Madrid, Avenida Complutense, s/n, Ciudad Universitaria, 28040 Madrid, Spain
| | - Vittorio Bellani
- Nanolab-Nanotechnology
Group, Departamento de Física Fundamental, Universidad de Salamanca, Plaza de la Merced, s/n., 37008-Salamanca, Spain
- Dipartimento
di Fisica, Università di Pavia, Via Agostino Bassi, 6, 27100 Pavia, Italy
| | - Francisco Domínguez-Adame
- GISC, Departamento
de Física de Materiales, Universidad
Complutense de Madrid, Avenida Complutense, s/n, Ciudad Universitaria, 28040 Madrid, Spain
| | - Enrique Diez
- Nanolab-Nanotechnology
Group, Departamento de Física Fundamental, Universidad de Salamanca, Plaza de la Merced, s/n., 37008-Salamanca, Spain
| | - Lucia Sorba
- NEST,
Scuola Normale Superiore e Istituto di Nanoscienze-CNR, Piazza san Silvestro 12, I-56127 Pisa, Italy
| | - Andrea Bertoni
- S3,
Istituto Nanoscienze-CNR, Via Campi 213/a, I-41125 Modena, Italy
| | - Guido Goldoni
- Dipartimento
di Scienze Fisiche, Informatiche e Matematiche, Università di Modena e Reggio Emilia, Via Campi 213/a, I-41125 Modena, Italy
| | - Francesco Rossella
- Dipartimento
di Scienze Fisiche, Informatiche e Matematiche, Università di Modena e Reggio Emilia, Via Campi 213/a, I-41125 Modena, Italy
| |
Collapse
|
18
|
Hu J, Yu F, Luo A, Pan XH, Zou J, Liu X, Xu G. Chiral Topological Superconductivity in Superconductor-Obstructed Atomic Insulator-Ferromagnetic Insulator Heterostructures. PHYSICAL REVIEW LETTERS 2024; 132:036601. [PMID: 38307042 DOI: 10.1103/physrevlett.132.036601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 12/08/2023] [Indexed: 02/04/2024]
Abstract
Implementing topological superconductivity (TSC) and Majorana states (MSs) is one of the most significant and challenging tasks in both fundamental physics and topological quantum computations. In this work, taking the obstructed atomic insulator (OAI) Nb_{3}Br_{8}, s-wave superconductor (SC) NbSe_{2}, and ferromagnetic insulator (FMI) CrI_{3} as an example, we propose a new setup to realize the 2D chiral TSC and MSs in the SC/OAI/FMI heterostructure, which could avoid the subband problem effectively and has the advantage of huge Rashba spin-orbit coupling. As a result, the TSC phase can be stabilized in a wide region of chemical potential and Zeeman splitting, and four distinct TSC phases with superconducting Chern number N=-1,-2,-3, 3 can be achieved. Moreover, a 2D Bogoliubov-de Gennes Hamiltonian based on the triangular lattice of obstructed Wannier charge centers, combined with the s-wave superconductivity paring and Zeeman splitting, is constructed to understand the whole topological phase diagram analytically. These results expand the application of OAIs and pave a new way to realize the TSC and MSs with unique advantages.
Collapse
Affiliation(s)
- Jingnan Hu
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Fei Yu
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Aiyun Luo
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiao-Hong Pan
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jinyu Zou
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xin Liu
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
- Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- Wuhan Institute of Quantum Technology, Wuhan 430206, China
| | - Gang Xu
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
- Institute for Quantum Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- Wuhan Institute of Quantum Technology, Wuhan 430206, China
| |
Collapse
|
19
|
Kitamura T, Daido A, Yanase Y. Spin-Triplet Superconductivity from Quantum-Geometry-Induced Ferromagnetic Fluctuation. PHYSICAL REVIEW LETTERS 2024; 132:036001. [PMID: 38307086 DOI: 10.1103/physrevlett.132.036001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 11/19/2023] [Accepted: 11/29/2023] [Indexed: 02/04/2024]
Abstract
We show that quantum geometry induces ferromagnetic fluctuation resulting in spin-triplet superconductivity. The criterion for ferromagnetic fluctuation is clarified by analyzing contributions from the effective mass and quantum geometry. When the non-Kramers band degeneracy is present near the Fermi surface, the Fubini-Study quantum metric strongly favors ferromagnetic fluctuation. Solving the linearized gap equation with the effective interaction obtained by the random phase approximation, we show that the spin-triplet superconductivity is mediated by quantum-geometry-induced ferromagnetic fluctuation.
Collapse
Affiliation(s)
- Taisei Kitamura
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Akito Daido
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Youichi Yanase
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| |
Collapse
|
20
|
Wei XK, Jalil AR, Rüßmann P, Ando Y, Grützmacher D, Blügel S, Mayer J. Atomic Diffusion-Induced Polarization and Superconductivity in Topological Insulator-Based Heterostructures. ACS NANO 2024; 18:571-580. [PMID: 38126781 PMCID: PMC10786152 DOI: 10.1021/acsnano.3c08601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 12/14/2023] [Accepted: 12/15/2023] [Indexed: 12/23/2023]
Abstract
The proximity effect at a highly transparent interface of an s-wave superconductor (S) and a topological insulator (TI) provides a promising platform to create Majorana zero modes in artificially designed heterostructures. However, structural and chemical issues pertinent to such interfaces have been poorly explored so far. Here, we report the discovery of Pd diffusion-induced polarization at interfaces between superconductive Pd1+x(Bi0.4Te0.6)2 (xPBT, 0 ≤ x ≤ 1) and Pd-intercalated Bi2Te3 by using atomic-resolution scanning transmission electron microscopy. Our quantitative image analysis reveals that nanoscale lattice strain and QL polarity synergistically suppress and promote Pd diffusion at the normal and parallel interfaces, formed between Te-Pd-Bi triple layers (TLs) and Te-Bi-Te-Bi-Te quintuple layers (QLs), respectively. Further, our first-principles calculations unveil that the superconductivity of the xPBT phase and topological nature of the Pd-intercalated Bi2Te3 phase are robust against the broken inversion symmetry. These findings point out the necessity of considering the coexistence of electric polarization with superconductivity and topology in such S-TI systems.
Collapse
Affiliation(s)
- Xian-Kui Wei
- Ernst
Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Abdur Rehman Jalil
- Peter
Grünberg Institute and JARA-FIT, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Philipp Rüßmann
- Institute
for Theoretical Physics and Astrophysics, University of Würzburg, 97074 Würzburg, Germany
- Peter
Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich GmbH and JARA, 52425 Jülich, Germany
| | - Yoichi Ando
- Physics
Institute II, University of Cologne, Zülpicher Straße 77, 50937 Köln, Germany
| | - Detlev Grützmacher
- Peter
Grünberg Institute and JARA-FIT, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Stefan Blügel
- Peter
Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich GmbH and JARA, 52425 Jülich, Germany
| | - Joachim Mayer
- Ernst
Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
- Central
Facility for Electron Microscopy, RWTH Aachen
University, Ahornstraße
55, 52074 Aachen, Germany
| |
Collapse
|
21
|
Wang S, Zhong M, Liu H, Ju M. Coexistence of topological node surface and Dirac fermions in phonon-mediated superconductor YB 2C 2. Phys Chem Chem Phys 2024; 26:1454-1461. [PMID: 38113107 DOI: 10.1039/d3cp03678b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
The interaction between nontrivial topology and superconductivity in condensed matter physics has attracted tremendous research interest as it could give rise to exotic phenomena. Herein, based on first-principles calculations, we investigate the electronic structures, mechanical properties, topological properties, dynamic stability, electron-phonon coupling (EPC), and superconducting properties of the synthesized real material YB2C2. It is a tetragonal structure with P4/mbm symmetry and exhibits excellent stability. The calculated electronic band structures reveal that a zero-dimension (0D) Dirac point and two-dimensional (2D) nodal surface coexist near the Fermi level. A spin-orbit coupling (SOC) Dirac point with the topological Fermi arc is observed on the (001) surface. These nodal surfaces are protected by a two-fold screw axis and time-reversal symmetry. Based on the Bardeen-Cooper-Schrieffer theory, the superconducting transition temperature (Tc) in the range 1.25-4.45 K with different Coulomb repulsion constant μ* for YB2C2 is estimated to be consistent with previous experimental results. In addition, the EPC is mainly from the coupling between the dx2-y2 and dz2 orbitals of the Y atom and low-energy phonon modes. The presence of superconductivity and nontrivial topological surface state in YB2C2 suggests that it may be a candidate material for topological superconductors.
Collapse
Affiliation(s)
- Siqi Wang
- School of Physical Science and Technology, Southwest University, Chongqing 400715, China.
| | - Mingmin Zhong
- School of Physical Science and Technology, Southwest University, Chongqing 400715, China.
| | - Haibo Liu
- School of Physical Science and Technology, Southwest University, Chongqing 400715, China.
| | - Meng Ju
- School of Physical Science and Technology, Southwest University, Chongqing 400715, China.
| |
Collapse
|
22
|
Chiang CC, Lee HC, Lin SC, Qu D, Chu MW, Chen CD, Chien CL, Huang SY. Unequivocal Identification of Spin-Triplet and Spin-Singlet Superconductors with Upper Critical Field and Flux Quantization. PHYSICAL REVIEW LETTERS 2023; 131:236003. [PMID: 38134800 DOI: 10.1103/physrevlett.131.236003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 11/13/2023] [Indexed: 12/24/2023]
Abstract
Spin-triplet superconductors play central roles in Majorana physics and quantum computing but are difficult to identify. We show the methods of kink-point upper critical field and flux quantization in superconducting rings can unequivocally identify spin-singlet, spin-triplet in centrosymmetric superconductors, and singlet-triplet admixture in noncentrosymmetric superconductors, as realized in γ-BiPd, β-Bi_{2}Pd, and α-BiPd, respectively. Our findings are essential for identifying triplet superconductors and exploring their quantum properties.
Collapse
Affiliation(s)
- C C Chiang
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
- Willian H. Miller III Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - H C Lee
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - S C Lin
- Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan
| | - D Qu
- Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan
- Center of Atomic Initiatives for New Materials, National Taiwan University, Taipei 10617, Taiwan
| | - M W Chu
- Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan
- Center of Atomic Initiatives for New Materials, National Taiwan University, Taipei 10617, Taiwan
| | - C D Chen
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - C L Chien
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
- Willian H. Miller III Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - S Y Huang
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
- Center of Atomic Initiatives for New Materials, National Taiwan University, Taipei 10617, Taiwan
| |
Collapse
|
23
|
Rivero JDH, Fleming C, Qi B, Feng L, Ge L. Robust Zero Modes in Non-Hermitian Systems without Global Symmetries. PHYSICAL REVIEW LETTERS 2023; 131:223801. [PMID: 38101337 DOI: 10.1103/physrevlett.131.223801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 11/02/2023] [Indexed: 12/17/2023]
Abstract
We present an approach to achieve zero modes in lattice models that do not rely on any symmetry or topology of the bulk, which are robust against disorder in the bulk of any type and strength. Such symmetry-free zero modes (SFZMs) are formed by attaching a single site or small cluster with zero mode(s) to the bulk, which serves as the "nucleus" that expands to the entire lattice. We identify the requirements on the couplings between this boundary and the bulk, which reveals that this approach is intrinsically non-Hermitian. We then provide several examples with either an arbitrary or structured bulk, forming spectrally embedded zero modes in the bulk continuum, midgap zero modes, and even restoring the "zeroness" of coupling or disorder-shifted topological corner states. Focusing on viable realizations using photonic lattices, we show that the resulting SFZM can be observed as the single lasing mode when optical gain is applied to the boundary.
Collapse
Affiliation(s)
- Jose D H Rivero
- College of Staten Island, CUNY, Staten Island, New York 10314, USA
- The Graduate Center, CUNY, New York, New York 10016, USA
| | - Courtney Fleming
- College of Staten Island, CUNY, Staten Island, New York 10314, USA
- The Graduate Center, CUNY, New York, New York 10016, USA
| | - Bingkun Qi
- College of Staten Island, CUNY, Staten Island, New York 10314, USA
- The Graduate Center, CUNY, New York, New York 10016, USA
| | - Liang Feng
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Li Ge
- College of Staten Island, CUNY, Staten Island, New York 10314, USA
- The Graduate Center, CUNY, New York, New York 10016, USA
| |
Collapse
|
24
|
Li G, Li M, Zhou X, Gao HJ. Toward large-scale, ordered and tunable Majorana-zero-modes lattice on iron-based superconductors. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2023; 87:016501. [PMID: 37963402 DOI: 10.1088/1361-6633/ad0c5c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 11/14/2023] [Indexed: 11/16/2023]
Abstract
Majorana excitations are the quasiparticle analog of Majorana fermions in solid materials. Typical examples are the Majorana zero modes (MZMs) and the dispersing Majorana modes. When probed by scanning tunneling spectroscopy, the former manifest as a pronounced conductance peak locating precisely at zero-energy, while the latter behaves as constant or slowly varying density of states. The MZMs obey non-abelian statistics and are believed to be building blocks for topological quantum computing, which is highly immune to the environmental noise. Existing MZM platforms include hybrid structures such as topological insulator, semiconducting nanowire or 1D atomic chains on top of a conventional superconductor, and single materials such as the iron-based superconductors (IBSs) and 4Hb-TaS2. Very recently, ordered and tunable MZM lattice has also been realized in IBS LiFeAs, providing a scalable and applicable platform for future topological quantum computation. In this review, we present an overview of the recent local probe studies on MZMs. Classified by the material platforms, we start with the MZMs in the iron-chalcogenide superconductors where FeTe0.55Se0.45and (Li0.84Fe0.16)OHFeSe will be discussed. We then review the Majorana research in the iron-pnictide superconductors as well as other platforms beyond the IBSs. We further review recent works on ordered and tunable MZM lattice, showing that strain is a feasible tool to tune the topological superconductivity. Finally, we give our summary and perspective on future Majorana research.
Collapse
Affiliation(s)
- Geng Li
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Hefei National Laboratory, Hefei 230088, People's Republic of China
| | - Meng Li
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Xingtai Zhou
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Hong-Jun Gao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| |
Collapse
|
25
|
Xie YM, Lantagne-Hurtubise É, Young AF, Nadj-Perge S, Alicea J. Gate-Defined Topological Josephson Junctions in Bernal Bilayer Graphene. PHYSICAL REVIEW LETTERS 2023; 131:146601. [PMID: 37862641 DOI: 10.1103/physrevlett.131.146601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 09/07/2023] [Indexed: 10/22/2023]
Abstract
Recent experiments on Bernal bilayer graphene (BLG) deposited on monolayer WSe_{2} revealed robust, ultraclean superconductivity coexisting with sizable induced spin-orbit coupling. Here, we propose BLG/WSe_{2} as a platform to engineer gate-defined planar topological Josephson junctions, where the normal and superconducting regions descend from a common material. More precisely, we show that if superconductivity in BLG/WSe_{2} is gapped and emerges from a parent state with intervalley coherence, then Majorana zero-energy modes can form in the barrier region upon applying weak in-plane magnetic fields. Our results spotlight a potential pathway for "internally engineered" topological superconductivity that minimizes detrimental disorder and orbital-magnetic-field effects.
Collapse
Affiliation(s)
- Ying-Ming Xie
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
| | - Étienne Lantagne-Hurtubise
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
| | - Andrea F Young
- Department of Physics, University of California at Santa Barbara, Santa Barbara, California 93106, USA
| | - Stevan Nadj-Perge
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA
| | - Jason Alicea
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
| |
Collapse
|
26
|
Banerjee A, Rahaman SR, Bondyopadhaya N. Electrical, thermal and thermoelectric transport in open long-range Kitaev chain. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 36:015303. [PMID: 37748479 DOI: 10.1088/1361-648x/acfcfd] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 09/25/2023] [Indexed: 09/27/2023]
Abstract
We study electrical, thermal and thermoelectric transport in a hybrid device consisting of a long-range Kitaev (LRK) chain coupled to two metallic leads at two ends. Electrical and thermal currents are calculated in this device under both voltage and thermal bias conditions. We find that the transport characteristics of the LRK chain are distinguishably different from its short-range counterpart, which is well known for hosting zero energy Majorana edge modes under some specific range of values of the model parameters. The emergence of massive Dirac fermions, the absence of gap closing at the topological phase transition point and some special features of the energy spectrum which are unique to the LRK chain, significantly alter electrical/thermal current vs. voltage/temperature bias characteristics in comparison with that of the short-range Kitaev chain. These novel transport characteristics of the LRK model can be helpful in understanding nontrivial topological phases of the LRK chain.
Collapse
Affiliation(s)
- Averi Banerjee
- Department of Basic Science and Humanities, Techno International Newtown, Kolkata 700156, India
| | - Sayeda Rafisa Rahaman
- Integrated Science Education & Research Centre, Visva-Bharati University, Santiniketan 731235, India
| | - Nilanjan Bondyopadhaya
- Integrated Science Education & Research Centre, Visva-Bharati University, Santiniketan 731235, India
| |
Collapse
|
27
|
Chu CG, Chen JJ, Wang AQ, Tan ZB, Li CZ, Li C, Brinkman A, Xiang PZ, Li N, Pan ZC, Lu HZ, Yu D, Liao ZM. Broad and colossal edge supercurrent in Dirac semimetal Cd 3As 2 Josephson junctions. Nat Commun 2023; 14:6162. [PMID: 37788988 PMCID: PMC10547728 DOI: 10.1038/s41467-023-41815-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 09/12/2023] [Indexed: 10/05/2023] Open
Abstract
Edge supercurrent has attracted great interest recently due to its crucial role in achieving and manipulating topological superconducting states. Proximity-induced superconductivity has been realized in quantum Hall and quantum spin Hall edge states, as well as in higher-order topological hinge states. Non-Hermitian skin effect, the aggregation of non-Bloch eigenstates at open boundaries, promises an abnormal edge channel. Here we report the observation of broad edge supercurrent in Dirac semimetal Cd3As2-based Josephson junctions. The as-grown Cd3As2 nanoplates are electron-doped by intrinsic defects, which enhance the non-Hermitian perturbations. The superconducting quantum interference indicates edge supercurrent with a width of ~1.6 μm and a magnitude of ~1 μA at 10 mK. The wide and large edge supercurrent is inaccessible for a conventional edge system and suggests the presence of non-Hermitian skin effect. A supercurrent nonlocality is also observed. The interplay between band topology and non-Hermiticity is beneficial for exploiting exotic topological matter.
Collapse
Affiliation(s)
- Chun-Guang Chu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871, Beijing, China
| | - Jing-Jing Chen
- Shenzhen Institute for Quantum Science and Engineering, Department of Physics, Southern University of Science and Technology, 518055, Shenzhen, China
- International Quantum Academy, 518048, Shenzhen, China
| | - An-Qi Wang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871, Beijing, China.
| | - Zhen-Bing Tan
- Shenzhen Institute for Quantum Science and Engineering, Department of Physics, Southern University of Science and Technology, 518055, Shenzhen, China.
- International Quantum Academy, 518048, Shenzhen, China.
| | - Cai-Zhen Li
- Shenzhen Institute for Quantum Science and Engineering, Department of Physics, Southern University of Science and Technology, 518055, Shenzhen, China
- International Quantum Academy, 518048, Shenzhen, China
| | - Chuan Li
- MESA+ Institute for Nanotechnology, University of Twente, 7500 AE, Enschede, The Netherlands
| | - Alexander Brinkman
- MESA+ Institute for Nanotechnology, University of Twente, 7500 AE, Enschede, The Netherlands
| | - Peng-Zhan Xiang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871, Beijing, China
| | - Na Li
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871, Beijing, China
| | - Zhen-Cun Pan
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871, Beijing, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering, Department of Physics, Southern University of Science and Technology, 518055, Shenzhen, China
| | - Dapeng Yu
- Shenzhen Institute for Quantum Science and Engineering, Department of Physics, Southern University of Science and Technology, 518055, Shenzhen, China
- International Quantum Academy, 518048, Shenzhen, China
- Hefei National Laboratory, 230088, Hefei, China
| | - Zhi-Min Liao
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871, Beijing, China.
- Hefei National Laboratory, 230088, Hefei, China.
| |
Collapse
|
28
|
Lahiri A, Choi SJ, Trauzettel B. Nonequilibrium Fractional Josephson Effect. PHYSICAL REVIEW LETTERS 2023; 131:126301. [PMID: 37802950 DOI: 10.1103/physrevlett.131.126301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 08/17/2023] [Indexed: 10/08/2023]
Abstract
Josephson tunnel junctions exhibit a supercurrent typically proportional to the sine of the superconducting phase difference ϕ. In general, a term proportional to cos(ϕ) is also present, alongside microscopic electronic retardation effects. We show that voltage pulses sharply varying in time prompt a significant impact of the cos(ϕ) term. Its interplay with the sin(ϕ) term results in a nonequilibrium fractional Josephson effect (NFJE) ∼sin(ϕ/2) in the presence of bound states close to zero frequency. Our microscopic analysis reveals that the interference of nonequilibrium virtual quasiparticle excitations is responsible for this phenomenon. We also analyze this phenomenon for topological Josephson junctions with Majorana bound states. Remarkably, the NFJE is independent of the ground state fermion parity unlike its equilibrium counterpart.
Collapse
Affiliation(s)
- Aritra Lahiri
- Institute for Theoretical Physics and Astrophysics, University of Würzburg, D-97074 Würzburg, Germany
| | - Sang-Jun Choi
- Institute for Theoretical Physics and Astrophysics, University of Würzburg, D-97074 Würzburg, Germany
| | - Björn Trauzettel
- Institute for Theoretical Physics and Astrophysics, University of Würzburg, D-97074 Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany
| |
Collapse
|
29
|
Fan YA, Li Y, Hu Y, Li Y, Long X, Liu H, Yang X, Nie X, Li J, Xin T, Lu D, Wan Y. Experimental quantum simulation of a topologically protected Hadamard gate via braiding Fibonacci anyons. Innovation (N Y) 2023; 4:100480. [PMID: 37560329 PMCID: PMC10407541 DOI: 10.1016/j.xinn.2023.100480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 07/09/2023] [Indexed: 08/11/2023] Open
Abstract
Topological quantum computation (TQC) is one of the most striking architectures that can realize fault-tolerant quantum computers. In TQC, the logical space and the quantum gates are topologically protected, i.e., robust against local disturbances. The topological protection, however, requires complicated lattice models and hard-to-manipulate dynamics; even the simplest system that can realize universal TQC-the Fibonacci anyon system-lacks a physical realization, let alone braiding the non-Abelian anyons. Here, we propose a disk model that can simulate the Fibonacci anyon system and construct the topologically protected logical spaces with the Fibonacci anyons. Via braiding the Fibonacci anyons, we can implement universal quantum gates on the logical space. Our disk model merely requires two physical qubits to realize three Fibonacci anyons at the boundary. By 15 sequential braiding operations, we construct a topologically protected Hadamard gate, which is to date the least-resource requirement for TQC. To showcase, we implement a topological Hadamard gate with two nuclear spin qubits, which reaches 97.18 % fidelity by randomized benchmarking. We further prove by experiment that the logical space and Hadamard gate are topologically protected: local disturbances due to thermal fluctuations result in a global phase only. As a platform-independent proposal, our work is a proof of principle of TQC and paves the way toward fault-tolerant quantum computation.
Collapse
Affiliation(s)
- Yu-ang Fan
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yingcheng Li
- State Key Laboratory of Surface Physics, Department of Physics, Center for Field Theory and Particle Physics, and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, and Shanghai Qi Zhi Institute, Shanghai 200030, China
| | - Yuting Hu
- School of Physics, Hangzhou Normal University, Hangzhou 311121, China
| | - Yishan Li
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xinyue Long
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Hongfeng Liu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xiaodong Yang
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xinfang Nie
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jun Li
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Tao Xin
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Dawei Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yidun Wan
- State Key Laboratory of Surface Physics, Department of Physics, Center for Field Theory and Particle Physics, and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, and Shanghai Qi Zhi Institute, Shanghai 200030, China
| |
Collapse
|
30
|
Zeng J, Li Q, Yang X, Xu DH, Wang R. Chiral-Flux-Phase-Based Topological Superconductivity in Kagome Systems with Mixed Edge Chiralities. PHYSICAL REVIEW LETTERS 2023; 131:086601. [PMID: 37683163 DOI: 10.1103/physrevlett.131.086601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/25/2023] [Accepted: 08/04/2023] [Indexed: 09/10/2023]
Abstract
Recent studies have attracted intense attention on the quasi-2D kagome superconductors AV_{3}Sb_{5} (A=K, Rb, and Cs) where the unexpected chiral flux phase (CFP) associates with the spontaneous time-reversal symmetry breaking in charge density wave states. Here, commencing from the 2-by-2 charge density wave phases, we bridge the gap between topological superconductivity and time-reversal asymmetric CFP in kagome systems. Several chiral topological superconductor (TSC) states featuring distinct Chern numbers emerge for an s-wave or a d-wave superconducting pairing symmetry. Importantly, these CFP-based TSC phases possess unique gapless edge modes with mixed chiralities (i.e., both positive and negative chiralities), but with the net chiralities consistent with the Bogoliubov-de Gennes Chern numbers. We further study the transport properties of a two-terminal junction, using Chern insulator or normal metal leads via atomic Green's function method with Landauer-Büttiker formalism. In both cases, the normal electron tunneling and the crossed Andreev reflection oscillate as the chemical potential changes, but together contribute to plateau transmissions (1 and 3/2, respectively) that exhibit robustness against disorder. These behaviors can be regarded as the signature of a TSC hosting edge states with mixed chiralities.
Collapse
Affiliation(s)
- Junjie Zeng
- Institute for Structure and Function and Department of Physics and Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing University, Chongqing 400044, People's Republic of China
| | - Qingming Li
- Department of Physics, Shijiazhuang University, Shijiazhuang, Hebei 050035, People's Republic of China
| | - Xun Yang
- Institute for Structure and Function and Department of Physics and Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing University, Chongqing 400044, People's Republic of China
| | - Dong-Hui Xu
- Institute for Structure and Function and Department of Physics and Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing University, Chongqing 400044, People's Republic of China
| | - Rui Wang
- Institute for Structure and Function and Department of Physics and Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing University, Chongqing 400044, People's Republic of China
- Center of Quantum materials and devices, Chongqing University, Chongqing 400044, People's Republic of China
| |
Collapse
|
31
|
Mandal M, Drucker NC, Siriviboon P, Nguyen T, Boonkird A, Lamichhane TN, Okabe R, Chotrattanapituk A, Li M. Topological Superconductors from a Materials Perspective. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:6184-6200. [PMID: 37637011 PMCID: PMC10448998 DOI: 10.1021/acs.chemmater.3c00713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 07/12/2023] [Indexed: 08/29/2023]
Abstract
Topological superconductors (TSCs) have garnered significant research and industry attention in the past two decades. By hosting Majorana bound states which can be used as qubits that are robust against local perturbations, TSCs offer a promising platform toward (nonuniversal) topological quantum computation. However, there has been a scarcity of TSC candidates, and the experimental signatures that identify a TSC are often elusive. In this Perspective, after a short review of the TSC basics and theories, we provide an overview of the TSC materials candidates, including natural compounds and synthetic material systems. We further introduce various experimental techniques to probe TSCs, focusing on how a system is identified as a TSC candidate and why a conclusive answer is often challenging to draw. We conclude by calling for new experimental signatures and stronger computational support to accelerate the search for new TSC candidates.
Collapse
Affiliation(s)
- Manasi Mandal
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
| | - Nathan C. Drucker
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- School
of Engineering and Applied Sciences, Harvard
University, Cambridge, Massachusetts 02138, United States
| | - Phum Siriviboon
- Department
of Physics, MIT, Cambridge, Massachusetts 02139, United States
| | - Thanh Nguyen
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
| | - Artittaya Boonkird
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
| | - Tej Nath Lamichhane
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
| | - Ryotaro Okabe
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Chemistry, MIT, Cambridge, Massachusetts 02139, United States
| | - Abhijatmedhi Chotrattanapituk
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Electrical Engineering and Computer Science, MIT, Cambridge, Massachusetts 02139, United States
| | - Mingda Li
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
| |
Collapse
|
32
|
Crépel V, Guerci D, Cano J, Pixley JH, Millis A. Topological Superconductivity in Doped Magnetic Moiré Semiconductors. PHYSICAL REVIEW LETTERS 2023; 131:056001. [PMID: 37595206 DOI: 10.1103/physrevlett.131.056001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 07/06/2023] [Indexed: 08/20/2023]
Abstract
We show that topological superconductivity may emerge upon doping of transition metal dichalcogenide heterobilayers above an integer-filling magnetic state of the topmost valence moiré band. The effective attraction between charge carriers is generated by an electric p-wave Feshbach resonance arising from interlayer excitonic physics and has a tunable strength, which may be large. Together with the low moiré carrier densities reachable by gating, this robust attraction enables access to the long-sought p-wave BEC-BCS transition. The topological protection arises from an emergent time reversal symmetry occurring when the magnetic order and long wavelength magnetic fluctuations do not couple different valleys. The resulting topological superconductor features helical Majorana edge modes, leading to half-integer quantized spin-thermal Hall conductivity and to charge currents induced by circularly polarized light or other time-reversal symmetry-breaking fields.
Collapse
Affiliation(s)
- Valentin Crépel
- Center for Computational Quantum Physics, Flatiron Institute, New York, New York 10010, USA
| | - Daniele Guerci
- Center for Computational Quantum Physics, Flatiron Institute, New York, New York 10010, USA
| | - Jennifer Cano
- Center for Computational Quantum Physics, Flatiron Institute, New York, New York 10010, USA
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - J H Pixley
- Center for Computational Quantum Physics, Flatiron Institute, New York, New York 10010, USA
- Department of Physics and Astronomy, Center for Materials Theory, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Andrew Millis
- Center for Computational Quantum Physics, Flatiron Institute, New York, New York 10010, USA
- Department of Physics, Columbia University, New York, New York 10027, USA
| |
Collapse
|
33
|
Yazdani A, von Oppen F, Halperin BI, Yacoby A. Hunting for Majoranas. Science 2023; 380:eade0850. [PMID: 37347870 DOI: 10.1126/science.ade0850] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 05/22/2023] [Indexed: 06/24/2023]
Abstract
Over the past decade, there have been considerable efforts to observe non-abelian quasiparticles in novel quantum materials and devices. These efforts are motivated by the goals of demonstrating quantum statistics of quasiparticles beyond those of fermions and bosons and of establishing the underlying science for the creation of topologically protected quantum bits. In this Review, we focus on efforts to create topological superconducting phases that host Majorana zero modes. We consider the lessons learned from existing experimental efforts, which are motivating both improvements to present platforms and the exploration of new approaches. Although the experimental detection of non-abelian quasiparticles remains challenging, the knowledge gained thus far and the opportunities ahead offer high potential for discovery and advances in this exciting area of quantum physics.
Collapse
Affiliation(s)
- Ali Yazdani
- Joseph Henry Laboratories and Department of Physics, Princeton University, Princeton, NJ 08540, USA
| | - Felix von Oppen
- Dahlem Center for Complex Quantum Systems and Fachbereich Physik, Freie Universität Berlin, 14195 Berlin, Germany
| | | | - Amir Yacoby
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| |
Collapse
|
34
|
Abstract
The topological properties of an object, associated with an integer called the topological invariant, are global features that cannot change continuously but only through abrupt variations, hence granting them intrinsic robustness. Engineered metamaterials (MMs) can be tailored to support highly nontrivial topological properties of their band structure, relative to their electronic, electromagnetic, acoustic and mechanical response, representing one of the major breakthroughs in physics over the past decade. Here, we review the foundations and the latest advances of topological photonic and phononic MMs, whose nontrivial wave interactions have become of great interest to a broad range of science disciplines, such as classical and quantum chemistry. We first introduce the basic concepts, including the notion of topological charge and geometric phase. We then discuss the topology of natural electronic materials, before reviewing their photonic/phononic topological MM analogues, including 2D topological MMs with and without time-reversal symmetry, Floquet topological insulators, 3D, higher-order, non-Hermitian and nonlinear topological MMs. We also discuss the topological aspects of scattering anomalies, chemical reactions and polaritons. This work aims at connecting the recent advances of topological concepts throughout a broad range of scientific areas and it highlights opportunities offered by topological MMs for the chemistry community and beyond.
Collapse
Affiliation(s)
- Xiang Ni
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, United States
- School of Physics and Electronics, Central South University, Changsha, Hunan 410083, China
| | - Simon Yves
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, United States
| | - Alex Krasnok
- Department of Electrical and Computer Engineering, Florida International University, Miami, Florida 33174, USA
| | - Andrea Alù
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, United States
- Department of Electrical Engineering, City College, The City University of New York, 160 Convent Avenue, New York, New York 10031, United States
- Physics Program, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, New York 10016, United States
| |
Collapse
|
35
|
Hess R, Legg HF, Loss D, Klinovaja J. Trivial Andreev Band Mimicking Topological Bulk Gap Reopening in the Nonlocal Conductance of Long Rashba Nanowires. PHYSICAL REVIEW LETTERS 2023; 130:207001. [PMID: 37267549 DOI: 10.1103/physrevlett.130.207001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 02/07/2023] [Accepted: 04/04/2023] [Indexed: 06/04/2023]
Abstract
We consider a one-dimensional Rashba nanowire in which multiple Andreev bound states in the bulk of the nanowire form an Andreev band. We show that, under certain circumstances, this trivial Andreev band can produce an apparent closing and reopening signature of the bulk band gap in the nonlocal conductance of the nanowire. Furthermore, we show that the existence of the trivial bulk reopening signature in nonlocal conductance is essentially unaffected by the additional presence of trivial zero-bias peaks in the local conductance at either end of the nanowire. The simultaneous occurrence of a trivial bulk reopening signature and zero-bias peaks mimics the basic features required to pass the so-called "topological gap protocol." Our results therefore provide a topologically trivial minimal model by which the applicability of this protocol can be benchmarked.
Collapse
Affiliation(s)
- Richard Hess
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| | - Henry F Legg
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| | - Daniel Loss
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| | - Jelena Klinovaja
- Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
| |
Collapse
|
36
|
Bauer NP, Budich JC, Trauzettel B, Calzona A. Quench-Probe Setup as Analyzer of Fractionalized Entanglement Spreading. PHYSICAL REVIEW LETTERS 2023; 130:190401. [PMID: 37243652 DOI: 10.1103/physrevlett.130.190401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 04/11/2023] [Indexed: 05/29/2023]
Abstract
We propose a novel spatially inhomogeneous setup for revealing quench-induced fractionalized excitations in entanglement dynamics. In this quench-probe setting, the region undergoing a quantum quench is tunnel coupled to a static region, the probe. Subsequently, the time-dependent entanglement signatures of a tunable subset of excitations propagating to the probe are monitored by energy selectivity. We exemplify the power of this generic approach by identifying a unique dynamical signature associated with the presence of an isolated Majorana zero mode in the postquench Hamiltonian. In this case excitations emitted from the topological part of the system give rise to a fractionalized jump of log(2)/2 in the entanglement entropy of the probe. This dynamical effect is highly sensitive to the localized nature of the Majorana zero mode, but does not require the preparation of a topological initial state.
Collapse
Affiliation(s)
- Nicolas P Bauer
- Institute of Theoretical Physics and Astrophysics, University of Würzburg, 97074 Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany
| | - Jan Carl Budich
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany
- Institute of Theoretical Physics, Technische Universität Dresden, 01062 Dresden, Germany
| | - Björn Trauzettel
- Institute of Theoretical Physics and Astrophysics, University of Würzburg, 97074 Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany
| | - Alessio Calzona
- Institute of Theoretical Physics and Astrophysics, University of Würzburg, 97074 Würzburg, Germany
- Würzburg-Dresden Cluster of Excellence ct.qmat, Germany
| |
Collapse
|
37
|
Máthé L, Kovács-Krausz Z, Botiz I, Grosu I, El Anouz K, El Allati A, Zârbo LP. Phonon-Assisted Tunneling through Quantum Dot Systems Connected to Majorana Bound States. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13101616. [PMID: 37242032 DOI: 10.3390/nano13101616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 05/05/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023]
Abstract
We theoretically analyze phonon-assisted tunneling transport in a quantum dot side connected to a Majorana bound state in a topological superconducting nanowire. We investigate the behavior of the current through the dot, for a range of experimentally relevant parameters, in the presence of one long-wave optical phonon mode. We consider the current-gate voltage, the current-bias voltage and the current-dot-Majorana coupling characteristics under the influence of the electron-phonon coupling. In the absence of electron-phonon interaction, the Majorana bound states suppress the current when the gate voltage matches the Fermi level, but the increase in the bias voltage counteracts this effect. In the presence of electron-phonon coupling, the current behaves similarly as a function of the renormalized gate voltage. As an added feature at large bias voltages, it presents a dip or a plateau, depending on the size of the dot-Majorana coupling. Lastly, we show that the currents are most sensitive to, and depend non-trivially on the parameters of the Majorana circuit element, in the regime of low temperatures combined with low voltages. Our results provide insights into the complex physics of quantum dot devices used to probe Majorana bound states.
Collapse
Affiliation(s)
- Levente Máthé
- Center of Advanced Research and Technologies for Alternative Energies, National Institute for R & D of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca, Romania
- Faculty of Physics, Babeș-Bolyai University, 1 Kogălniceanu, 400084 Cluj-Napoca, Romania
| | - Zoltán Kovács-Krausz
- Department of Physics, Institute of Physics, Budapest University of Technology and Economics, Műegyetem rkp. 3, H-1111 Budapest, Hungary
| | - Ioan Botiz
- Faculty of Physics, Babeș-Bolyai University, 1 Kogălniceanu, 400084 Cluj-Napoca, Romania
- Interdisciplinary Research Institute in Bio-Nano-Sciences, Babeș-Bolyai University, 42 Treboniu Laurian, 400271 Cluj-Napoca, Romania
| | - Ioan Grosu
- Faculty of Physics, Babeș-Bolyai University, 1 Kogălniceanu, 400084 Cluj-Napoca, Romania
| | - Khadija El Anouz
- Laboratory of R & D in Engineering Sciences, Faculty of Sciences and Techniques Al-Hoceima, Abdelmalek Essaadi University, Tetouan 93000, Morocco
| | - Abderrahim El Allati
- Laboratory of R & D in Engineering Sciences, Faculty of Sciences and Techniques Al-Hoceima, Abdelmalek Essaadi University, Tetouan 93000, Morocco
| | - Liviu P Zârbo
- Center of Advanced Research and Technologies for Alternative Energies, National Institute for R & D of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca, Romania
| |
Collapse
|
38
|
Chiu SP, Mishra V, Li Y, Zhang FC, Kirchner S, Lin JJ. Tuning interfacial two-component superconductivity in CoSi 2/TiSi 2 heterojunctions via TiSi 2 diffusivity. NANOSCALE 2023; 15:9179-9186. [PMID: 37145162 DOI: 10.1039/d2nr05864b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We report the observation of enhanced interfacial two-component superconductivity possessing a dominant triplet component in nonmagnetic CoSi2/TiSi2 superconductor/normal-metal planar heterojunctions. This is accomplished through the detection of odd-frequency spin-triplet even-parity Cooper pairs in the diffusive normal-metal component of T-shaped proximity junctions. We show that by modifying the diffusivity of the normal-metal part, the transition temperature enhancement can be tuned by a factor of up to 2.3 while the upper critical field increases by up to a factor of 20. Our data suggest that the C49 phase of TiSi2, which is stabilized in confined geometries, underlies this enhancement. These findings are addressed via a Ginzburg-Landau model and the quasi-classical theory. We also relate our findings to the enigmatic 3-K phase reported in Sr2 RuO4.
Collapse
Affiliation(s)
- Shao-Pin Chiu
- Department of Electrophysics & Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Vivek Mishra
- Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Yu Li
- Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Fu-Chun Zhang
- Kavli Institute for Theoretical Sciences & CAS Center for Excellence in Topological Quantum Computation & HKU-UCAS Joint Institute of Theoretical and Computational Physics at Beijing, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Stefan Kirchner
- Department of Electrophysics & Center for Emergent Functional Matter Science & Center for Theoretical and Computational Physics, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.
| | - Juhn-Jong Lin
- Department of Electrophysics & Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.
| |
Collapse
|
39
|
Díez-Mérida J, Díez-Carlón A, Yang SY, Xie YM, Gao XJ, Senior J, Watanabe K, Taniguchi T, Lu X, Higginbotham AP, Law KT, Efetov DK. Symmetry-broken Josephson junctions and superconducting diodes in magic-angle twisted bilayer graphene. Nat Commun 2023; 14:2396. [PMID: 37100775 PMCID: PMC10133447 DOI: 10.1038/s41467-023-38005-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 04/06/2023] [Indexed: 04/28/2023] Open
Abstract
The coexistence of gate-tunable superconducting, magnetic and topological orders in magic-angle twisted bilayer graphene provides opportunities for the creation of hybrid Josephson junctions. Here we report the fabrication of gate-defined symmetry-broken Josephson junctions in magic-angle twisted bilayer graphene, where the weak link is gate-tuned close to the correlated insulator state with a moiré filling factor of υ = -2. We observe a phase-shifted and asymmetric Fraunhofer pattern with a pronounced magnetic hysteresis. Our theoretical calculations of the junction weak link-with valley polarization and orbital magnetization-explain most of these unconventional features. The effects persist up to the critical temperature of 3.5 K, with magnetic hysteresis observed below 800 mK. We show how the combination of magnetization and its current-induced magnetization switching allows us to realise a programmable zero-field superconducting diode. Our results represent a major advance towards the creation of future superconducting quantum electronic devices.
Collapse
Affiliation(s)
- J Díez-Mérida
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain
| | - A Díez-Carlón
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain
| | - S Y Yang
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain
| | - Y-M Xie
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - X-J Gao
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - J Senior
- IST Austria, Am Campus 1, 3400, Klosterneuburg, Austria
| | - K Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - T Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - X Lu
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain
| | | | - K T Law
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Dmitri K Efetov
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, 08860, Spain.
| |
Collapse
|
40
|
Giwa R, Hosur P. Superconductor Vortex Spectrum Including Fermi Arc States in Time-Reversal Symmetric Weyl Semimetals. PHYSICAL REVIEW LETTERS 2023; 130:156402. [PMID: 37115867 DOI: 10.1103/physrevlett.130.156402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 12/21/2022] [Accepted: 03/27/2023] [Indexed: 06/19/2023]
Abstract
Using semiclassics to surmount the hurdle of bulk-surface inseparability, we derive the superconductor vortex spectrum in nonmagnetic Weyl semimetals and show that it stems from the Berry phase of orbits made of Fermi arcs on opposite surfaces and bulk chiral modes. Tilting the vortex transmutes it between bosonic, fermionic, and supersymmetric, produces periodic peaks in the density of states that signify novel nonlocal Majorana modes, and yields a thickness-independent spectrum at magic "magic angles." We propose (Nb,Ta)P as candidate materials and tunneling spectroscopy as the ideal experiment.
Collapse
Affiliation(s)
- Rauf Giwa
- University of Houston, Houston, Texas 77204, USA
| | - Pavan Hosur
- University of Houston, Houston, Texas 77204, USA
- Texas Center for Superconductivity at the University of Houston, Houston, Texas 77204, USA
| |
Collapse
|
41
|
Akbari A, Thalmeier P. Magnetic excitations in the helical Rashba superconductor. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 35:265601. [PMID: 36947885 DOI: 10.1088/1361-648x/acc6ad] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 03/22/2023] [Indexed: 06/18/2023]
Abstract
We investigate the magnetic excitation spectrum in the helical state of a noncentrosymmetric superconductor with inversion symmetry breaking and strong Rashba spin-orbit coupling. For this purpose we derive the general expressions of the dynamical spin response functions under the presence of strong Rashba splitting of conduction bands, superconducting gap and external field which lead to stabilization of Cooper pairs with finite overall momentum in a helical state. The latter is characterized by momentum space regions of paired and unpaired states with different quasiparticle dispersions. The magnetic response is determined by i) excitations within and between both paired and unpaired regions ii) anomalous coherence factors and iii) additional spin matrix elements due to helical Rashba spin texture of bands. We show that as a consequence typical correlated real space and spin space anisotropies appear in the dynamical susceptibility which would be observable as a characteristic fingerprint for a helical superconducting state in inelastic neutron scattering investigations.
Collapse
Affiliation(s)
- Alireza Akbari
- Max Planck Institute for the Chemical Physics of Solids, D-01187 Dresden, Germany
| | - Peter Thalmeier
- Max Planck Institute for the Chemical Physics of Solids, D-01187 Dresden, Germany
| |
Collapse
|
42
|
Sufyan A, Larsson JA. Topological Nodal Surface and Quadratic Dirac Semimetal States and van Hove Singularities in ScH 3 and LuH 3 Superconductors. ACS OMEGA 2023; 8:9607-9613. [PMID: 36936326 PMCID: PMC10018709 DOI: 10.1021/acsomega.3c00207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
The coexistence of non-trivial topology and superconductivity in a material may induce a novel physical phenomenon known as topological superconductivity. Topological superconductors have been the subject of intense research, yet there are severe limitations in their application due to a lack of suitable materials. Topological nodal surface semimetals with nearly flat nodal surfaces near the Fermi level can be promising materials to achieve topological superconductivity. Here, we use first-principles calculations to examine the topological electronic characteristics of two new superconductors, ScH3 and LuH3, at both ambient and high pressures. Our studies show that both ScH3 and LuH3 have van Hove singularities, which confirms their superconductivity. Interestingly, both materials host topological nodal surface states under the protection of time reversal and spatial inversion symmetries in the absence of spin-orbit coupling (SOC). These nodal surfaces are distinguished by a pair of unique drum-head-like surface states not previously observed in nodal surface semimetals. Moreover, the nodal surfaces transform into essential spin-orbit quadratic Dirac points when SOC is included. Our findings demonstrate that ScH3 and LuH3 are good candidates to investigate the exotic properties of both nodal surface semimetals (NSSMs) and quadratic Dirac semimetal states and also provide a platform to explore the coexistence of topology and superconductivity in NSSMs with promising applications in high-speed electronics and topological quantum computing.
Collapse
|
43
|
Ziesen A, Altland A, Egger R, Hassler F. Statistical Majorana Bound State Spectroscopy. PHYSICAL REVIEW LETTERS 2023; 130:106001. [PMID: 36962051 DOI: 10.1103/physrevlett.130.106001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Tunnel spectroscopy data for the detection of Majorana bound states (MBS) is often criticized for its proneness to misinterpretation of genuine MBS with low-lying Andreev bound states. Here, we suggest a protocol removing this ambiguity by extending single shot measurements to sequences performed at varying system parameters. We demonstrate how such sampling, which we argue requires only moderate effort for current experimental platforms, resolves the statistics of Andreev side lobes, thus providing compelling evidence for the presence or absence of a Majorana center peak.
Collapse
Affiliation(s)
- Alexander Ziesen
- JARA Institute for Quantum Information, RWTH Aachen University, 52056 Aachen, Germany
| | - Alexander Altland
- Institut für Theoretische Physik, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany
| | - Reinhold Egger
- Institut für Theoretische Physik, Heinrich-Heine-Universität, D-40225 Düsseldorf, Germany
| | - Fabian Hassler
- JARA Institute for Quantum Information, RWTH Aachen University, 52056 Aachen, Germany
| |
Collapse
|
44
|
Guhr T. Statistical Topology-Distribution and Density Correlations of Winding Numbers in Chiral Systems. ENTROPY (BASEL, SWITZERLAND) 2023; 25:383. [PMID: 36832749 PMCID: PMC9955588 DOI: 10.3390/e25020383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/15/2023] [Accepted: 02/16/2023] [Indexed: 06/18/2023]
Abstract
Statistical Topology emerged as topological aspects continue to gain importance in many areas of physics. It is most desirable to study topological invariants and their statistics in schematic models that facilitate the identification of universalities. Here, the statistics of winding numbers and of winding number densities are addressed. An introduction is given for readers with little background knowledge. Results that my collaborators and I obtained in two recent works on proper random matrix models for the chiral unitary and symplectic cases are reviewed, avoiding a technically detailed discussion. There is a special focus on the mapping of topological problems to spectral ones as well as on the first glimpse of universality.
Collapse
Affiliation(s)
- Thomas Guhr
- Fakultät für Physik, Universtät Duisburg-Essen, 47048 Duisburg, Germany
| |
Collapse
|
45
|
Lima ACP, Ribeiro RCB, Correa JH, Deus F, Figueira MS, Continentino MA. Thermoelectric properties of topological chains coupled to a quantum dot. Sci Rep 2023; 13:1508. [PMID: 36707603 PMCID: PMC9883525 DOI: 10.1038/s41598-023-28491-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 01/19/2023] [Indexed: 01/28/2023] Open
Abstract
Topological one-dimensional superconductors can sustain zero energy modes protected by different kinds of symmetries in their extremities. Observing these excitations in the form of Majorana fermions is one of the most intensive quests in condensed matter physics. We are interested in another class of one-dimensional topological systems in this work, namely topological insulators. Which present symmetry-protected end modes with robust properties and do not require the low temperatures necessary for topological superconductivity. We consider a device in the form of a single electron transistor coupled to the simplest kind of topological insulators, namely chains of atoms with hybridized sp orbitals. We study the thermoelectric properties of the device in the trivial, non-trivial topological phases and at the quantum topological transition of the chains. We show that the device's electrical conductance and the Wiedemann-Franz ratio at the topological transition have universal values at very low temperatures. The conductance and thermopower of the device with diatomic sp-chains, at their topological transition, give direct evidence of fractional charges in the system. The former has an anomalous low-temperature behavior, attaining a universal value that is a consequence of the double degeneracy of the system due to the presence of zero energy modes. On the other hand, the system can be tuned to exhibit high values of the thermoelectric figure of merit and the power factor at high temperatures.
Collapse
Affiliation(s)
- A. C. P. Lima
- grid.418228.50000 0004 0643 8134Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud, 150, Urca, Rio de Janeiro, RJ 22290-180 Brazil
| | - R. C. Bento Ribeiro
- grid.418228.50000 0004 0643 8134Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud, 150, Urca, Rio de Janeiro, RJ 22290-180 Brazil
| | - J. H. Correa
- grid.441911.80000 0001 1818 386XUniversidad Tecnológica Del Perú, Nathalio Sanchez, 125, 15046 Lima, Peru
| | - Fernanda Deus
- grid.412211.50000 0004 4687 5267Universidade do Estado do Rio de Janeiro, Rodovia Presidente Dutra km 298, Resende, RJ 27537-000 Brazil
| | - M. S. Figueira
- grid.411173.10000 0001 2184 6919Instituto de Física, Universidade Federal Fluminense, Av. Litorânea s/N, Niterói, RJ 24210-340 Brazil
| | - Mucio A. Continentino
- grid.418228.50000 0004 0643 8134Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud, 150, Urca, Rio de Janeiro, RJ 22290-180 Brazil
| |
Collapse
|
46
|
Potts H, Aspegren M, Debbarma R, Lehmann S, Thelander C. Large-bias spectroscopy of Yu-Shiba-Rusinov states in a double quantum dot. NANOTECHNOLOGY 2023; 34:135002. [PMID: 36595334 DOI: 10.1088/1361-6528/aca90e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
We have performed tunnel transport spectroscopy on a quantum dot (QD) molecule proximitized by a superconducting contact. In such a system, the scattering between QD spins and Bogoliubov quasiparticles leads to the formation of Yu-Shiba-Rusinov (YSR) states within the superconducting gap. In this work, we investigate interactions appearing when one- and two-electron spin states in a double-QD energetically align with the superconducting gap edge. We find that the inter-dot spin-triplet state interacts considerably stronger with the superconductor than the corresponding singlet, pointing to stronger screening. By forming a ring molecule with a significant orbital contribution to the effectiveg-factor, we observe interactions of all four spin-orbital one-electron states with the superconductor under a weak magnetic field.
Collapse
Affiliation(s)
- Heidi Potts
- Division of Solid State Physics and NanoLund, Lund University, SE-221 00 Lund, Sweden
| | - Markus Aspegren
- Division of Solid State Physics and NanoLund, Lund University, SE-221 00 Lund, Sweden
| | - Rousan Debbarma
- Division of Solid State Physics and NanoLund, Lund University, SE-221 00 Lund, Sweden
| | - Sebastian Lehmann
- Division of Solid State Physics and NanoLund, Lund University, SE-221 00 Lund, Sweden
| | - Claes Thelander
- Division of Solid State Physics and NanoLund, Lund University, SE-221 00 Lund, Sweden
| |
Collapse
|
47
|
Venu V, Xu P, Mamaev M, Corapi F, Bilitewski T, D'Incao JP, Fujiwara CJ, Rey AM, Thywissen JH. Unitary p-wave interactions between fermions in an optical lattice. Nature 2023; 613:262-267. [PMID: 36631646 DOI: 10.1038/s41586-022-05405-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 10/03/2022] [Indexed: 01/13/2023]
Abstract
Exchange-antisymmetric pair wavefunctions in fermionic systems can give rise to unconventional superconductors and superfluids1-3. The realization of these states in controllable quantum systems, such as ultracold gases, could enable new types of quantum simulations4-8, topological quantum gates9-11 and exotic few-body states12-15. However, p-wave and other antisymmetric interactions are weak in naturally occurring systems16,17, and their enhancement via Feshbach resonances in ultracold systems has been limited by three-body loss18-24. Here we create isolated pairs of spin-polarized fermionic atoms in a multiorbital three-dimensional optical lattice. We spectroscopically measure elastic p-wave interaction energies of strongly interacting pairs of atoms near a magnetic Feshbach resonance. The interaction strengths are widely tunable by the magnetic field and confinement strength, and yet collapse onto a universal curve when rescaled by the harmonic energy and length scales of a single lattice site. The absence of three-body processes enables the observation of elastic unitary p-wave interactions, as well as coherent oscillations between free-atom and interacting-pair states. All observations are compared both to an exact solution using a p-wave pseudopotential and to numerical solutions using an ab initio interaction potential. The understanding and control of on-site p-wave interactions provides a necessary component for the assembly of multiorbital lattice models25,26 and a starting point for investigations of how to protect such systems from three-body recombination in the presence of tunnelling, for instance using Pauli blocking and lattice engineering27,28.
Collapse
Affiliation(s)
- Vijin Venu
- Department of Physics and CQIQC, University of Toronto, Toronto, Ontario, Canada
| | - Peihang Xu
- Department of Physics and CQIQC, University of Toronto, Toronto, Ontario, Canada
| | - Mikhail Mamaev
- JILA, NIST and Department of Physics, University of Colorado, Boulder, CO, USA.,Center for Theory of Quantum Matter, University of Colorado, Boulder, CO, USA
| | - Frank Corapi
- Department of Physics and CQIQC, University of Toronto, Toronto, Ontario, Canada
| | - Thomas Bilitewski
- JILA, NIST and Department of Physics, University of Colorado, Boulder, CO, USA.,Center for Theory of Quantum Matter, University of Colorado, Boulder, CO, USA.,Department of Physics, Oklahoma State University, Stillwater, OK, USA
| | - Jose P D'Incao
- JILA, NIST and Department of Physics, University of Colorado, Boulder, CO, USA
| | - Cora J Fujiwara
- Department of Physics and CQIQC, University of Toronto, Toronto, Ontario, Canada.
| | - Ana Maria Rey
- JILA, NIST and Department of Physics, University of Colorado, Boulder, CO, USA. .,Center for Theory of Quantum Matter, University of Colorado, Boulder, CO, USA.
| | - Joseph H Thywissen
- Department of Physics and CQIQC, University of Toronto, Toronto, Ontario, Canada.
| |
Collapse
|
48
|
Chomaz L, Ferrier-Barbut I, Ferlaino F, Laburthe-Tolra B, Lev BL, Pfau T. Dipolar physics: a review of experiments with magnetic quantum gases. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 86:026401. [PMID: 36583342 DOI: 10.1088/1361-6633/aca814] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Since the achievement of quantum degeneracy in gases of chromium atoms in 2004, the experimental investigation of ultracold gases made of highly magnetic atoms has blossomed. The field has yielded the observation of many unprecedented phenomena, in particular those in which long-range and anisotropic dipole-dipole interactions (DDIs) play a crucial role. In this review, we aim to present the aspects of the magnetic quantum-gas platform that make it unique for exploring ultracold and quantum physics as well as to give a thorough overview of experimental achievements. Highly magnetic atoms distinguish themselves by the fact that their electronic ground-state configuration possesses a large electronic total angular momentum. This results in a large magnetic moment and a rich electronic transition spectrum. Such transitions are useful for cooling, trapping, and manipulating these atoms. The complex atomic structure and large dipolar moments of these atoms also lead to a dense spectrum of resonances in their two-body scattering behaviour. These resonances can be used to control the interatomic interactions and, in particular, the relative importance of contact over dipolar interactions. These features provide exquisite control knobs for exploring the few- and many-body physics of dipolar quantum gases. The study of dipolar effects in magnetic quantum gases has covered various few-body phenomena that are based on elastic and inelastic anisotropic scattering. Various many-body effects have also been demonstrated. These affect both the shape, stability, dynamics, and excitations of fully polarised repulsive Bose or Fermi gases. Beyond the mean-field instability, strong dipolar interactions competing with slightly weaker contact interactions between magnetic bosons yield new quantum-stabilised states, among which are self-bound droplets, droplet assemblies, and supersolids. Dipolar interactions also deeply affect the physics of atomic gases with an internal degree of freedom as these interactions intrinsically couple spin and atomic motion. Finally, long-range dipolar interactions can stabilise strongly correlated excited states of 1D gases and also impact the physics of lattice-confined systems, both at the spin-polarised level (Hubbard models with off-site interactions) and at the spinful level (XYZ models). In the present manuscript, we aim to provide an extensive overview of the various related experimental achievements up to the present.
Collapse
Affiliation(s)
- Lauriane Chomaz
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
- Physikalisches Institut der Universität Heidelberg, Im Neuenheimer Feld 226, 69120 Heidelberg, Germany
| | - Igor Ferrier-Barbut
- Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
- Université Paris-Saclay, Institut d'Optique Graduate School, CNRS, Laboratoire Charles Fabry, 91127 Palaiseau, France
| | - Francesca Ferlaino
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
- Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria
| | - Bruno Laburthe-Tolra
- Université Sorbonne Paris Nord, Laboratoire de Physique des Lasers, F-93430 Villetaneuse, France
- CNRS, UMR 7538, LPL, F-93430 Villetaneuse, France
| | - Benjamin L Lev
- Departments of Physics and Applied Physics and Ginzton Laboratory, Stanford University, Stanford, CA 94305, United States of America
| | - Tilman Pfau
- Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| |
Collapse
|
49
|
Liu CX, Wang G, Dvir T, Wimmer M. Tunable Superconducting Coupling of Quantum Dots via Andreev Bound States in Semiconductor-Superconductor Nanowires. PHYSICAL REVIEW LETTERS 2022; 129:267701. [PMID: 36608192 DOI: 10.1103/physrevlett.129.267701] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 05/18/2022] [Accepted: 11/23/2022] [Indexed: 06/17/2023]
Abstract
Semiconductor quantum dots have proven to be a useful platform for quantum simulation in the solid state. However, implementing a superconducting coupling between quantum dots mediated by a Cooper pair has so far suffered from limited tunability and strong suppression. This has limited applications such as Cooper pair splitting and quantum dot simulation of topological Kitaev chains. In this Letter, we propose how to mediate tunable effective couplings via Andreev bound states in a semiconductor-superconductor nanowire connecting two quantum dots. We show that in this way it is possible to individually control both the coupling mediated by Cooper pairs and by single electrons by changing the properties of the Andreev bound states with easily accessible experimental parameters. In addition, the problem of coupling suppression is greatly mitigated. We also propose how to experimentally extract the coupling strengths from resonant current in a three-terminal junction. Our proposal will enable future experiments that have not been possible so far.
Collapse
Affiliation(s)
- Chun-Xiao Liu
- Qutech and Kavli Institute of Nanoscience, Delft University of Technology, Delft 2600 GA, Netherlands
| | - Guanzhong Wang
- Qutech and Kavli Institute of Nanoscience, Delft University of Technology, Delft 2600 GA, Netherlands
| | - Tom Dvir
- Qutech and Kavli Institute of Nanoscience, Delft University of Technology, Delft 2600 GA, Netherlands
| | - Michael Wimmer
- Qutech and Kavli Institute of Nanoscience, Delft University of Technology, Delft 2600 GA, Netherlands
| |
Collapse
|
50
|
Baldelli N, Bhattacharya U, González-Cuadra D, Lewenstein M, Graß T. Detecting Majorana Zero Modes via Strong Field Dynamics. ACS OMEGA 2022; 7:47424-47430. [PMID: 36570179 PMCID: PMC9773937 DOI: 10.1021/acsomega.2c07169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 11/24/2022] [Indexed: 06/17/2023]
Abstract
We propose a protocol to detect topological phase transitions of one-dimensional p-wave superconductors from their harmonic emission spectra in strong fields. Specifically, we identify spectral features due to radiating edge modes, which characterize the spectrum and the density of states in the topological phase and are absent in the trivial phase. These features allow us to define a measurable signature, obtained from emission measurements, that unambiguously differentiates between the two phases. Local probing provides insight into the localized and topologically protected nature of the modes. The presented results establish that high-harmonic spectroscopy can be used as an all-optical tool for the detection of Majorana zero modes.
Collapse
Affiliation(s)
- Niccolò Baldelli
- Institut
de Ciencies Fotoniques (ICFO), The Barcelona Institute of Science
and Technology, 08860Castelldefels, Barcelona, Spain
| | - Utso Bhattacharya
- Institut
de Ciencies Fotoniques (ICFO), The Barcelona Institute of Science
and Technology, 08860Castelldefels, Barcelona, Spain
| | - Daniel González-Cuadra
- Institut
de Ciencies Fotoniques (ICFO), The Barcelona Institute of Science
and Technology, 08860Castelldefels, Barcelona, Spain
- Institute
for Theoretical Physics, University of Innsbruck, 6020Innsbruck, Austria
- Institute
for Quantum Optics and Quantum Information, Austrian Academy of Sciences, 6020Innsbruck, Austria
| | - Maciej Lewenstein
- Institut
de Ciencies Fotoniques (ICFO), The Barcelona Institute of Science
and Technology, 08860Castelldefels, Barcelona, Spain
- Institución
Catalana de Investigación y Esteudios Avanzados (ICREA), Pg. Lluis Companys 23, 08010Barcelona, Barcelona, Spain
| | - Tobias Graß
- Institut
de Ciencies Fotoniques (ICFO), The Barcelona Institute of Science
and Technology, 08860Castelldefels, Barcelona, Spain
- Donostia
International Physics Center (DIPC), Paseo Manuel de Lardizábal 4, 20018San Sebastián, Gipuzkoa, Spain
- Ikerbasque, Maria Diaz de Haro 3, 48013Bilbao, Biscay, Spain
| |
Collapse
|