Majorana fermion induced nonlocal current correlations in spin-orbit coupled superconducting wires

Liu, Jie; Zhang, Fuchun; Law, K. T.

doi:10.1103/physrevb.88.064509

Cited by 78 publications

(86 citation statements)

References 44 publications

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“…A generalization of the result given in Ref. 19, shows that at zero bias the differential conductance is given by…”

Section: Arxiv:14010078v1 [Cond-matmes-hall] 31 Dec 2013mentioning

confidence: 52%

“…5 and 8 still hold. Throughout the paper we have been using the differential Fano factors, as they more clearly demonstrate the physical behavior of electrons at a given energy [19], but we could instead use the more easily measurable Fano factor for the integrated noise and current. In the low voltage regime, the correction terms due to finite bias in both the differential conductance and noise go as…”

Section: Arxiv:14010078v1 [Cond-matmes-hall] 31 Dec 2013mentioning

confidence: 99%

“…We consider the same experimental geometry as in [18] and [19]: we have a grounded topological superconducting wire, with each Majorana bound state coupled to a normal lead. We model quasiparticle poisoning by coupling fermion reservoirs to each Majorana mode.…”

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confidence: 99%

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Proposal to measure the quasiparticle poisoning time of Majorana bound states

Colbert

Lee

2014

Phys. Rev. B

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We propose a method of measuring the fermion parity lifetime of Majorana fermion modes due to quasiparticle poisoning. We model quasiparticle poisoning by coupling the Majorana modes to electron reservoirs, explicitly breaking parity conservation in the system. This poisoning broadens and shortens the resonance peak associated with Majorana modes. In a two lead geometry, the poisoning decreases the correlation in current noise between the two leads from the maximal value characteristic of crossed Andreev reflection. The latter measurement allows for calculation of the poisoning rate even if temperature is much higher than the resonance width.The promise of topologically robust quantum computation has been a major motivation in condensed matter physics over the past decade. In such schemes quantum information is not stored locally but is stored in a global state of the system. In this way systems are protected against decoherence by local perturbations. A simple and potentially realizable platform for non-local quantum information storage is in systems with Majorana fermions, which split a single fermionic mode into two spatially separated Majorana bound states. Systems with Majorana qubits are only protected under perturbations that preserve fermion parity; that is, they only involve the transfer of Cooper pairs [13]. Perturbations that switch the fermion parity of the system, involving unpaired electrons, dubbed quasiparticle poisoning, will change the state of a Majorana qubit. The time scale of this poisoning rate is then a limiting factor for performing quantum computations. Recent theoretical calculations show that this poisoning rate may be problematically large for performing adiabatic gate operations [14].In light of this challenge, it is essential to be able to measure this poisoning rate. There have been several proposals to measure the rate based on SQUIDs in topological superconductor/superconductor heterosturctures [4,15], a quantum dot coupled to a topological superconducting wire [16], or direct measurement of parity relax- ation times [17]. In this article we propose a relatively simple experimental setup that doesn't require an interference measurement, based on the two lead transport experiments proposed by Nilsson et al.[18] and Liu et al. [19]. Our proposed measurement gives a direct probe of the breakdown of non-locality due to quasiparticle poisoning.We consider the same experimental geometry as in [18] and [19]: we have a grounded topological superconducting wire, with each Majorana bound state coupled to a normal lead. We model quasiparticle poisoning by coupling fermion reservoirs to each Majorana mode. We consider the limit with k B T, eV ∆, so that the Majorana modes are the only modes accessible to electrons tunneling from the leads. Explicitly, our effective Hamiltonian is(1) Heregives the lead and bath Hamiltonian, E M gives the splitting of the coupled Majorana modes, t α gives the coupling to the leads with electron creation operators c † α at the interface, and δ α gives the co...

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“…A generalization of the result given in Ref. 19, shows that at zero bias the differential conductance is given by…”

Section: Arxiv:14010078v1 [Cond-matmes-hall] 31 Dec 2013mentioning

confidence: 52%

Section: Arxiv:14010078v1 [Cond-matmes-hall] 31 Dec 2013mentioning

confidence: 99%

See 1 more Smart Citation

Proposal to measure the quasiparticle poisoning time of Majorana bound states

Colbert

Lee

2014

Phys. Rev. B

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“…These two methods are consistent with each other. The calculation of the Andreev reflection coefficient through the effective model can be found in the appendix or in [47], and can be expressed simply as…”

Section: Resultsmentioning

confidence: 99%

“…Thus, it is necessary to add another STM lead to detect the electron transmission or the crossed Andreev reflection between the two leads [47–48]. This can directly reveal the information of the DOS.…”

Section: Resultsmentioning

confidence: 99%

Revealing the interference effect of Majorana fermions in a topological Josephson junction

Liu

Song

2018

Beilstein J. Nanotechnol.

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We study theoretically the local density of states (DOS) in a topological Josephson junction. We show that the well-known 4π Josephson effect originates from the interference effect between two Majorana fermions (MFs) that are localized at the Josephson junction. In addition, the DOS for electrons (holes) shows the 4π interference information along each parity conserved energy spectrum. The DOS displays a 2π period oscillation when two trivial states interfere with each other. This means that the DOS information may be used to distinguish the MFs from trivial localized states. We suggest that the interference effect and the DOS can be detected by using two STM leads or two normal leads. A single side lead can only detect the Andreev reflection tunneling process in the junction, which cannot reveal information about the interference effect in general. However, using two side leads, we can reveal information about the interference effect of the MFs as well as the DOS by combining Andreev reflection with the electron transmission process.

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