scholarly journals Quantum Interference Effects in Quantum Dot Molecular With Majorana Bound States

2021 ◽  
Vol 8 ◽  
Author(s):  
Feng Chi ◽  
Jing Wang ◽  
Tian-Yu He ◽  
Zhen-Guo Fu ◽  
Ping Zhang ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Bound States ◽  
Quantum Information Processing ◽  
Bound State ◽  
Double Quantum ◽  
Zero Energy ◽  
Non Invasive ◽  
Majorana Bound States ◽  
Quantum Interference Effect ◽  
Core Issues

Non-invasive detection of the Majorana bound state (MBSs), a kind of quasiparticle without charge and mass, is one of the core issues in current condensed matter physics. Here we study in theory the quantum interference effect in parallel-coupled double quantum dots which are connected either by Majorana bound states (MBSs) or regular fermions. We find that the zero-energy conductance develops a sharp peak when the dots are connected by the MBSs, whereas that in the case of the dots are coupled via regular fermions shows a valley. By varying the coupling strength between the dots and the electron reservoirs, the conductance in the two structures changes in different ways. By comparing the properties of the linear conductance in the two systems, the information of the MBSs formed at the two ends of a topological superconductor nanowire then can be inferred. We also find that the MBSs in the present structure also induces the Fano effect, and is favorable in quantum information processing.

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.

Quantum interference effect in double quantum wells

1995 ◽  
Vol 35 (1-3) ◽  
pp. 372-375
Author(s):  
Xinghua Wang ◽  
Qi Yu ◽  
Reino Laiho ◽  
Chengfang Li ◽  
Jian Liu ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Interference Effect ◽  
Quantum Interference ◽  
Double Quantum ◽  
Quantum Interference Effect

scholarly journals Delocalisation of Majorana quasiparticles in plaquette–nanowire hybrid system

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Aksel Kobiałka ◽  
Tadeusz Domański ◽  
Andrzej Ptok
Keyword(s):  
Bound States ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Two Dimensional ◽  
Edge States ◽  
Zero Energy ◽  
One Dimensional ◽  
Majorana Bound States ◽  
Entire Structure ◽  
Majorana Modes

Abstract Interplay between superconductivity, spin-orbit coupling and magnetic field can lead to realisation of the topologically non–trivial states which in finite one dimensional nanowires are manifested by emergence of a pair of zero-energy Majorana bound states. On the other hand, in two dimensional systems the chiral edge states can appear. We investigate novel properties of the bound states in a system of mixed dimensionality, composed of one-dimensional nanowire connected with two-dimensional plaquette. We study this system, assuming either its part or the entire structure to be in topologically non–trivial superconducting state. Our results show delocalisation of the Majorana modes, upon leaking from the nanowire to the plaquette with some tendency towards its corners.

EXCHANGE FIELD EFFECT ON THE ANDREEV BOUND STATE STUDIED BY FERROMAGNET/HIGH Tc SUPERCONDUCTOR INTERFACE

2005 ◽  
Vol 19 (01n03) ◽  
pp. 495-497 ◽  
Author(s):  
K.-W. NG ◽  
MARIO FREAMAT
Keyword(s):  
Bound States ◽  
Bound State ◽  
Exchange Field ◽  
Zero Energy ◽  
S Wave ◽  
High Tc ◽  
Andreev Bound States ◽  
High Tc Superconductor ◽  
Energy Peak ◽  
Andreev Bound State

We have prepared Ag / BSCCO and Fe / Ag / BSCCO planar junctions to study the effect of Fe exchange field on the tunneling spectra. The junctions were constructed so that the tunneling direction is within the ab-plane, either along the maximum or minimum gap direction. Andreev bound states were observed as zero energy peak in the minimum gap direction. The exchange field caused major splitting of the zero energy peak, which did not occur in Ag / BSCCO junctions. We had detected a few percent (6 to 7%) of s-wave subcomponent at the interface in many of these junctions. This s-wave subcomponent had a Tc of about 20K.

scholarly journals Electronic Transport Through Double Quantum Dot Coupled to Majorana Bound States and Ferromagnetic Leads

2021 ◽  
Vol 8 ◽  
Author(s):  
Li-Wen Tang ◽  
Wei-Guo Mao
Keyword(s):  
Quantum Dot ◽  
Coupling Strength ◽  
Bound States ◽  
High Efficiency ◽  
Energy Levels ◽  
Electrical Current ◽  
Function Technique ◽  
Double Quantum ◽  
Majorana Bound States ◽  
Double Quantum Dot

We have studied theoretically the properties of electrical current and tunnel magnetoresistance (TMR) through a serially connected double quantum dot (DQD) sandwiched between two ferromagnetic leads by using the nonequilibrium Green’s function technique. We consider that each of the DQD couples to one mode of the Majorana bound states (MBSs) formed at the ends of a topological superconductor nanowire with spin-dependent coupling strength. By adjusting the sign of the spin polarization of dot–MBS coupling strength and the arrangement of magnetic moments of the two leads, the currents’ magnitude can be effectively enhanced or suppressed. Under some conditions, a negative TMR emerges which is useful in detection of the MBSs, a research subject currently under extensive investigations. Moreover, the amplitude of the TMR can be adjusted in a large regime by variation of several system parameters, such as direct hybridization strength between the MBSs or the dots and the positions of the dots’ energy levels. Such tunable currents and TMR may also find use in high-efficiency spintronic devices or information processes.

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