Observation of the 4π-periodic Josephson effect in indium arsenide nanowires

  title={Observation of the 4$\pi$-periodic Josephson effect in indium arsenide nanowires},
  author={Dominique Laroche and Dani{\"e}l Bouman and David J. van Woerkom and Alex Proutski and Chaitanya Murthy and Dmitry I. Pikulin and C. Nayak and Ruben J. J. van Gulik and Jesper Nyg{\aa}rd and Peter Krogstrup and L. P. Kouwenhoven and Attila Geresdi},
  journal={Nature Communications},
Quantum computation by non-Abelian Majorana zero modes (MZMs) offers an approach to achieve fault tolerance by encoding quantum information in the non-local charge parity states of semiconductor nanowire networks in the topological superconductor regime. Thus far, experimental studies of MZMs chiefly relied on single electron tunneling measurements, which lead to the decoherence of the quantum information stored in the MZM. As a next step towards topological quantum computation, charge parity… 
Superconducting spin properties of Majorana nanowires and the associated spin-orbit coupling driven transverse supercurrent
It is difficult to unambiguously confirm the existence of Majorana zero modes (MZMs) due to the absence of smoking-gun signatures in charge transport measurements. Recent studies suggest that the
Thermoelectric Effect in a Correlated Quantum Dot Side-Coupled to Majorana Bound States
Large value of 100% spin-polarized or pure spin thermopower emerges even in the absence of Zeeman splitting in the QD or magnetic electrodes because the MBSs are coupled to electrons of only one certain spin direction in theQD due to the chiral nature of the Majorana fermions.
Absence of supercurrent sign reversal in a topological junction with a quantum dot
Experimental techniques to verify Majoranas are of current interest. A prominent test is the effect of Majoranas on the Josephson current between two wires linked via a normal junction. Here, we
Magnetoelectrically tunable Andreev bound state spectra and spin polarization in p -wave Josephson junctions
We demonstrate how the boundary-driven reconstruction of the superconducting order parameter can be employed to manipulate the zero-energy Majorana bound states (MBSs) occurring in a topological
Transport studies in a gate-tunable three-terminal Josephson junction
Josephson junctions with three or more superconducting leads have been predicted to exhibit topological effects in the presence of few conducting modes within the interstitial normal material. Such
Topological superconductivity in planar Josephson junctions: Narrowing down to the nanowire limit
We theoretically study topological planar Josephson junctions (JJs) formed from spin-orbit-coupled two-dimensional electron gases (2DEGs) proximitized by two superconductors and subjected to an
Thermodynamics in topological Josephson junctions
We study the thermodynamic properties of topological Josephson junctions using a quantum spin Hall (QSH) insulator-based junction as an example. In particular, we propose that phase-dependent
Full proximity treatment of topological superconductors in Josephson-junction architectures
Experiments on planar Josephson junction architectures have recently been shown to provide an alternative way of creating topological superconductors hosting accessible Majorana modes. These
Transport experiments in semiconductor-superconductor hybrid Majorana devices
As the condensed matter analog of Majorana fermion, Majorana zero-mode is well known as a building block of fault-tolerant topological quantum computing. In this review, we focus on the recent
Josephson junction of finite-size superconductors on a topological insulator under a magnetic field
We theoretically study a Josephson junction formed by two finite-size $s$-wave SCs on a topological insulator under a magnetic field. At certain conditions, the junction hosts the chiral Majorana


Observation of the fractional ac Josephson effect: the signature of Majorana particles
Topological superconductors which support Majorana fermions are thought to be realized in one-dimensional semiconducting wires coupled to a superconductor [1–3]. Such excitations are expected to
Observation of Majorana Fermions in a Nb-InSb Nanowire-Nb Hybrid Quantum Device
We report on the observation of excitation of Majorana fermions in a Nb-InSb nanowire quantum dot-Nb hybrid system. The InSb nanowire quantum dot is formed between the two Nb contacts by weak
Non-equilibrium 8π Josephson effect in atomic Kitaev wires
A signature of Majorana quasi-particles is identified, qualitatively different from the behaviour of a conventional superconductor, which can be detected in cold atom systems using alkaline-earth-like atoms.
Evidence of Majorana fermions in an Al - InAs nanowire topological superconductor
Majorana fermions are the only fermionic particles that are expected to be their own antiparticles. While elementary particles of the Majorana type were not identified yet, quasi-particles with
ac Josephson effect in finite-length nanowire junctions with Majorana modes.
The ac Josephson transients are protected against decay by quasiparticle poisoning as a consequence of the quantum Zeno effect, which fixes the parity of Majorana qubits, and may be effectively used to detect MBS.
Exciting Andreev pairs in a superconducting atomic contact
The Josephson effect is established through spectroscopic measurements of superconducting atomic contacts, which depend on the atomic configuration and on the phase difference between the superconductors, are in complete agreement with theory.
Scalable designs for quasiparticle-poisoning-protected topological quantum computation with Majorana zero modes
We present designs for scalable quantum computers composed of qubits encoded in aggregates of four or more Majorana zero modes, realized at the ends of topological superconducting wire segments that
Spin-resolved Andreev levels and parity crossings in hybrid superconductor-semiconductor nanostructures.
A direct measurement of the Zeeman effect on the Andreev levels of a semiconductor quantum dot with large electron g-factor, strongly coupled to a conventional superconductor with a large critical magnetic field allows spin degeneracy to be lifted without destroying superconductivity.
Microwave spectroscopy of spinful Andreev bound states in ballistic semiconductor Josephson junctions
The superconducting proximity effect in semiconductor nanowires has recently enabled the study of new superconducting architectures, such as gate-tunable superconducting qubits and multiterminal
Majorana fermions and a topological phase transition in semiconductor-superconductor heterostructures.
The measurement of the supercurrent through the junction allows one to discern topologically distinct phases and observe a topological phase transition by simply changing the in-plane magnetic field or the gate voltage, which will be a direct demonstration of the existence of Majorana particles.