TY - JOUR

T1 - Evidence of topological superconductivity in planar Josephson junctions

AU - Fornieri, Antonio

AU - Whiticar, Alexander M.

AU - Setiawan, F.

AU - Marín, Elías Portolés

AU - Drachmann, Asbjørn C. C.

AU - Keselman, Anna

AU - Gronin, Sergei

AU - Thomas, Candice

AU - Wang, Tian

AU - Kallaher, Ray

AU - Gardner, Geoffrey C.

AU - Berg, Erez

AU - Manfra, Michael J.

AU - Stern, Ady

AU - Marcus, Charles M.

AU - Nichele, Fabrizio

N1 - [Qdev]

PY - 2019/5/2

Y1 - 2019/5/2

N2 - Majorana zero modes are quasiparticle states localized at the boundaries of topological superconductors that are expected to be ideal building blocks for fault-tolerant quantum computing. Several observations of zero-bias conductance peaks measured in tunneling spectroscopy above a critical magnetic field have been reported as experimental indications of Majorana zero modes in superconductor/semiconductor nanowires. On the other hand, two dimensional systems offer the alternative approach to confine Ma jorana channels within planar Josephson junctions, in which the phase difference {\phi} between the superconducting leads represents an additional tuning knob predicted to drive the system into the topological phase at lower magnetic fields. Here, we report the observation of phase-dependent zero-bias conductance peaks measured by tunneling spectroscopy at the end of Josephson junctions realized on a InAs/Al heterostructure. Biasing the junction to {\phi} ~ {\pi} significantly reduces the critical field at which the zero-bias peak appears, with respect to {\phi} = 0. The phase and magnetic field dependence of the zero-energy states is consistent with a model of Majorana zero modes in finite-size Josephson junctions. Besides providing experimental evidence of phase-tuned topological superconductivity, our devices are compatible with superconducting quantum electrodynamics architectures and scalable to complex geometries needed for topological quantum computing.

AB - Majorana zero modes are quasiparticle states localized at the boundaries of topological superconductors that are expected to be ideal building blocks for fault-tolerant quantum computing. Several observations of zero-bias conductance peaks measured in tunneling spectroscopy above a critical magnetic field have been reported as experimental indications of Majorana zero modes in superconductor/semiconductor nanowires. On the other hand, two dimensional systems offer the alternative approach to confine Ma jorana channels within planar Josephson junctions, in which the phase difference {\phi} between the superconducting leads represents an additional tuning knob predicted to drive the system into the topological phase at lower magnetic fields. Here, we report the observation of phase-dependent zero-bias conductance peaks measured by tunneling spectroscopy at the end of Josephson junctions realized on a InAs/Al heterostructure. Biasing the junction to {\phi} ~ {\pi} significantly reduces the critical field at which the zero-bias peak appears, with respect to {\phi} = 0. The phase and magnetic field dependence of the zero-energy states is consistent with a model of Majorana zero modes in finite-size Josephson junctions. Besides providing experimental evidence of phase-tuned topological superconductivity, our devices are compatible with superconducting quantum electrodynamics architectures and scalable to complex geometries needed for topological quantum computing.

KW - cond-mat.mes-hall

KW - cond-mat.supr-con

U2 - 10.1038/s41586-019-1068-8

DO - 10.1038/s41586-019-1068-8

M3 - Journal article

C2 - 31019303

VL - 569

SP - 89

EP - 92

JO - Nature

JF - Nature

SN - 0028-0836

ER -