Josephson effect in junctions of conventional and topological superconductors

Zazunov, Alex; Iks, Albert; Alvarado, Miguel; Yeyati, A. Levy; Egger, Reinhold

doi:10.3762/bjnano.9.158

Cited by 15 publications

(19 citation statements)

References 86 publications

(166 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…C). However, we find that the contributions of the higher energy Andreev bound states, neglected in the low-energy model, also contribute to the ground state critical current due to residual s-wave pairing in the higher energy excitations, even after the topological phase transition [42]. These additional contributions disguise the oscillatory behavior of I C contributed by the MBS showing vanishing critical currents for certain values of V Z in the low-energy model.…”

mentioning

confidence: 76%

See 1 more Smart Citation

Influence of the Majorana nonlocality on the supercurrent

Schuray¹,

Yeyati²,

Recher³

2018

Phys. Rev. B

View full text Add to dashboard Cite

We study the equilibrium Josephson current between an s-wave superconductor and a topological superconducting nanowire with Majorana bound states (MBS) at its ends. Within a low-energy model we show analytically that the non-locality of the MBS allows for a finite supercurrent to flow that otherwise would vanish. In particular, we find the critical current to be a function of the difference in the spin canting angles of the Majorana wave functions at the location of the tunnel contact. We complement our analytical calculations by numerically solving the full tight binding model and show how to extract the main features of the low-energy model from the critical current using available experimental techniques.

show abstract

mentioning

confidence: 76%

“…So in general, contributions to the Josephson current originate from residual s-wave pairing in the SOCNW [42]. Josephson current in the low-energy model.-In the topologically non-trivial phase of the SOCNW the low energy physics is governed by the two MBS described by Hermitian operators γ 1 and γ 2 satisfying {γ i , γ j } = 2δ ij .…”

mentioning

confidence: 99%

Influence of the Majorana nonlocality on the supercurrent

Schuray¹,

Yeyati²,

Recher³

2018

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…For completeness, we include in the Hamiltonian the phase φ, which is important when the chain is coupled in a Josephson circuit, although it does not play an important role in the behavior of the spin excitations. 12,23,24,36 For φ = 0, the Hamiltonian is invariant under time reversal symmetry. In addition, in absence of superconductivity (∆ = 0), for µ = 0, the Hamiltonian is invariant under the electron hole transformation c † jσ → (−1) j c jσ .…”

Section: Modelmentioning

confidence: 99%

Entangled end states with fractionalized spin projection in a time-reversal-invariant topological superconducting wire

Aligia

Arrachea

2018

Phys. Rev. B

View full text Add to dashboard Cite

We study the ground state and low-energy subgap excitations of a finite wire of a time-reversalinvariant topological superconductor (TRITOPS) with spin-orbit coupling. We solve the problem analytically for a long chain of a specific one-dimensional lattice model in the electron-hole symmetric configuration and numerically for other cases of the same model. We present results for the spin density of excitations in long chains with an odd number of particles. The total spin projection along the axis of the spin-orbit coupling Sz = ±1/2 is distributed with fractions ±1/4 localized at both ends, and shows even-odd alternation along the sites of the chain. We calculate the localization length of these excitations and find that it can be well approximated by a simple analytical expression. We show that the energy E of the lowest subgap excitations of the finite chain defines tunneling and entanglement between end states. We discuss the effect of a Zeeman coupling ∆Z on one of the ends of the chain only. For ∆Z < E, the energy difference of excitations with opposite spin orientation is ∆Z /2, consistent with a spin projection ±1/4. We argue that these physical features are not model dependent and can be experimentally observed in TRITOPS wires under appropriate conditions.

show abstract

“…While the Majorana contribution qualitatively confirms the analytical findings, higher energy contributions conceal most of the Majorana features. The higher energy contributions come from a residual s-wave pairing in the TSC [158,162]. The critical current still shows jumps at parity crossings, however, in contrast to the Majorana contributions the magnitude of the critical current is reduced with increased Zeeman field.…”

Section: High Energy Contributions and Tight Binding Approachmentioning

confidence: 94%

“…In the model discussed in the previous section the focus has been placed on a superconducting JJ between a topological superconductor and a non topological superconductor [158,159,162]. In such a JJ, the current phase relation features a 2π periodicity like the traditional Josephson effect.…”

Section: Tsc-tsc Junction In Silicenementioning

confidence: 99%

Transport signatures of Majorana bound states in superconducting hybrid structures

Schuray

Frombach

Park

et al. 2020

Eur. Phys. J. Spec. Top.

View full text Add to dashboard Cite

In this minireview, we outline the recent experimental and theoretical progress in the creation, characterization and manipulation of Majorana bound states (MBSs) in semiconductor-superconductor (SC) hybrid structures. After an introductory overview of the broader field we specifically focus on four of our recent projects in this direction. We show that the emergence of Fano resonances in the differential conductance in a normal lead-Majorana nanowire-quantum dot setup can be exploited to determine if a single MBS is contacted by the normal lead and the quantum dot providing an experimental test of the nonlocality of MBSs. In the second project, the tunnel-coupling to two MBSs in an s-wave SC-Majorana nanowire Josephson junction (JJ) leads to a finite contribution of the MBSs to the equilibrium Josephson current probing directly the local spin-singlet contribution of the Majorana pair. We then shift our focus from MBSs forming in nanowire systems to MBSs forming in topological JJs. In a single sheet of buckled silicene with proximity induced superconductivity two local electric fields can be used to tune the junction between a topologically trivial and topologically non-trivial regime. In a Corbino geometry topological Josephson junction two MBSs harbored in Josephson vortices can rotate along the JJ and, in the course of this, will be exchanged periodically in the phase difference of the JJ. The tunneling current in a metal tip coupled to the JJ is shown to exhibit signs of the anyonic braiding phase of two MBSs.

show abstract

Josephson effect in junctions of conventional and topological superconductors

Cited by 15 publications

References 86 publications

Influence of the Majorana nonlocality on the supercurrent

Influence of the Majorana nonlocality on the supercurrent

Entangled end states with fractionalized spin projection in a time-reversal-invariant topological superconducting wire

Transport signatures of Majorana bound states in superconducting hybrid structures

Contact Info

Product

Resources

About