scholarly journals Andreev bound states versus Majorana bound states in quantum dot-nanowire-superconductor hybrid structures: Trivial versus topological zero-bias conductance peaks

2017 ◽  
Vol 96 (7) ◽  
Author(s):  
Chun-Xiao Liu ◽  
Jay D. Sau ◽  
Tudor D. Stanescu ◽  
S. Das Sarma
Keyword(s):  
Quantum Dot ◽  
Bound States ◽  
Hybrid Structures ◽  
Zero Bias ◽  
Andreev Bound States ◽  
Majorana Bound States ◽  
Zero Bias Conductance

scholarly journals Topological isoconductance signatures in Majorana nanowires

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
L. S. Ricco ◽  
J. E. Sanches ◽  
Y. Marques ◽  
M. de Souza ◽  
M. S. Figueira ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Transport Properties ◽  
Spin Polarization ◽  
Bound States ◽  
Spin Asymmetry ◽  
Experimental Protocol ◽  
Zero Bias ◽  
Topological Superconductor ◽  
Hybrid Device ◽  
Majorana Bound States

AbstractWe consider transport properties of a hybrid device composed by a quantum dot placed between normal and superconducting reservoirs, and coupled to a Majorana nanowire: a topological superconducting segment hosting Majorana bound states (MBSs) at the opposite ends. It is demonstrated that if highly nonlocal and nonoverlapping MBSs are formed in the system, the zero-bias Andreev conductance through the dot exhibits characteristic isoconductance profiles with the shape depending on the spin asymmetry of the coupling between the dot and the topological superconductor. Otherwise, for overlapping MBSs with less degree of nonlocality, the conductance is insensitive to the spin polarization and the isoconductance signatures disappear. This allows to propose an alternative experimental protocol for probing the nonlocality of the MBSs in Majorana nanowires.

scholarly journals Spatial Rabi oscillations between Majorana bound states and quantum dots

2018 ◽  
Vol 9 ◽  
pp. 1527-1535
Author(s):  
Jun-Hui Zheng ◽  
Dao-Xin Yao ◽  
Zhi Wang
Keyword(s):  
Quantum Dot ◽  
Bound States ◽  
Bound State ◽  
Double Quantum ◽  
Energy Splitting ◽  
Rabi Oscillations ◽  
Andreev Bound States ◽  
Majorana Bound States ◽  
Nonlocal Quantum ◽  
Equal Amplitude

Background: A Majorana bound state is a superconducting quasiparticle that is the superposition of particle and hole with equal amplitude. We propose a verification of this amplitude equality by analyzing the spatial Rabi oscillations of the quantum states of a quantum dot that is tunneling-coupled to the Majorana bound states. Results: We find two resonant Rabi driving energies that correspond to the energy splitting due to the coupling of two spatially separated Majorana bound states. The resulting Rabi oscillating frequencies from these two different resonant driving energies are identical for the Majorana bound states, while different for ordinary Andreev bound states. We further study a double-quantum-dot setup and find a nonlocal quantum correlation between them that is mediated by two Majorana bound states. This nonlocal correlation has the signature of additional resonant driving energies. Conclusion: Our method can be used to distinguish between Majorana bound states and Andreev bound states. It also gives a precise measurement of the energy splitting between two Majorana bound states.

scholarly journals Reproducing topological properties with quasi-Majorana states

2019 ◽  
Vol 7 (5) ◽  
Author(s):  
Adriaan Vuik ◽  
Bas Nijholt ◽  
Anton Akhmerov ◽  
Michael Wimmer
Keyword(s):  
Bound States ◽  
Josephson Effect ◽  
Tunnel Barrier ◽  
Topological Properties ◽  
Zero Energy ◽  
Tunneling Spectrum ◽  
Zero Bias ◽  
Andreev Bound States ◽  
Zero Bias Conductance ◽  
Coupling Strengths

Andreev bound states in hybrid superconductor-semiconductor devices can have near-zero energy in the topologically trivial regime as long as the confinement potential is sufficiently smooth. These quasi-Majorana states show zero-bias conductance features in a topologically trivial phase, mimicking spatially separated topological Majorana states. We show that in addition to the suppressed coupling between the quasi-Majorana states, also the coupling of these states across a tunnel barrier to the outside is exponentially different for increasing magnetic field. As a consequence, quasi-Majorana states mimic most of the proposed Majorana signatures: quantized zero-bias peaks, the 4\pi4π Josephson effect, and the tunneling spectrum in presence of a normal quantum dot. We identify a quantized conductance dip instead of a peak in the open regime as a distinguishing feature of true Majorana states in addition to having a bulk topological transition. Because braiding schemes rely only on the ability to couple to individual Majorana states, the exponential control over coupling strengths allows to also use quasi-Majorana states for braiding. Therefore, while the appearance of quasi-Majorana states complicates the observation of topological Majorana states, it opens an alternative route towards braiding of non-Abelian anyons and protected quantum computation.

Superconducting Current-Phase Relation and Andreev Bound States in Nb/Au/YBa2Cu3Ox Josephson Heterojunctions

2003 ◽  
Vol 17 (10n12) ◽  
pp. 569-578 ◽  
Author(s):  
G. A. Ovsyannikov ◽  
P. V. Komissinski ◽  
Yu. V. Kislinski ◽  
Z. G. Ivanov
Keyword(s):  
Phase Relation ◽  
Bound States ◽  
Measurement Accuracy ◽  
Current Phase ◽  
Zero Bias ◽  
Shapiro Steps ◽  
Andreev Bound States ◽  
Conductance Peak ◽  
Zero Bias Conductance ◽  
Superconducting Current

Nb / Au / YBa 2 Cu 3 O x heterojunctions in (001) and (1 1 20)-oriented YBa 2 Cu 3 O x films have been fabricated. I-V curves of both kinds of heterojunctions show pronounced superconducting current. As affected by microwave radiation Shapiro steps at voltages hf/ 4e arise in the I-V curves of Nb / Au / YBa 2 Cu 3 O x (001) heterojunctions implying the double periodic (~ sin 2φ) superconducting current-phase relation. However, in the case of Nb / Au / YBa 2 Cu 3 O x (1 1 20) heterojunctions Shapiro steps have been observed in the I-V curves at voltages hf/ 2e only supporting a sinusoidal (~ sin φ) superconducting current-phase relation within measurement accuracy. A zero bias conductance peak associated with zero-energy Andreev bound states occurs in the I-V curve of the Nb / Au / YBa 2 Cu 3 O x (1 1 20) heterojunctions. We discuss the experimental results in terms of the d-wave symmetrical superconducting order parameter in YBCO.

scholarly journals Origin of bias-independent conductance plateaus and zero-bias conductance peaks in Bi2Se3/NbSe2 hybrid structures

2017 ◽  
Vol 96 (7) ◽  
Author(s):  
Hui Li ◽  
Tong Zhou ◽  
Jun He ◽  
Huan-Wen Wang ◽  
Huachen Zhang ◽  
...  
Keyword(s):  
Hybrid Structures ◽  
Zero Bias ◽  
Zero Bias Conductance

Odd–Even Effect of the Persistent Current in a Quantum Dot Ring with Embedded Majorana Bound States

2015 ◽  
Vol 84 (2) ◽  
pp. 024707 ◽  
Author(s):  
Wei-Jiang Gong ◽  
Ying Zhao ◽  
Zhen Gao ◽  
Guangyu Yi ◽  
Xin Zhang
Keyword(s):  
Quantum Dot ◽  
Bound States ◽  
Persistent Current ◽  
Majorana Bound States
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