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—quasiparticle states localized at the boundaries of topological superconductors—are expected to be ideal building blocks for fault-tolerant quantum computing1,2. Several observations of zero-bias conductance peaks measured by tunnelling spectroscopy above a critical magnetic field have been reported as experimental indications of Majorana zero modes in superconductor–semiconductor nanowires3–8. On the other hand, two-dimensional systems offer the alternative approach of confining Majorana channels within planar Josephson junctions, in which the phase difference φ between the superconducting leads represents an additional tuning knob that is predicted to drive the system into the topological phase at lower magnetic fields than for a system without phase bias9,10. Here we report the observation of phase-dependent zero-bias conductance peaks measured by tunnelling spectroscopy at the end of Josephson junctions realized on a heterostructure consisting of aluminium on indium arsenide. Biasing the junction to φ ≈ π reduces the critical field at which the zero-bias peak appears, with respect to φ = 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. As well as providing experimental evidence of phase-tuned topological superconductivity, our devices are compatible with superconducting quantum electrodynamics architectures11 and are scalable to the complex geometries needed for topological quantum computing9,12,13.
AB - Majorana zero modes—quasiparticle states localized at the boundaries of topological superconductors—are expected to be ideal building blocks for fault-tolerant quantum computing1,2. Several observations of zero-bias conductance peaks measured by tunnelling spectroscopy above a critical magnetic field have been reported as experimental indications of Majorana zero modes in superconductor–semiconductor nanowires3–8. On the other hand, two-dimensional systems offer the alternative approach of confining Majorana channels within planar Josephson junctions, in which the phase difference φ between the superconducting leads represents an additional tuning knob that is predicted to drive the system into the topological phase at lower magnetic fields than for a system without phase bias9,10. Here we report the observation of phase-dependent zero-bias conductance peaks measured by tunnelling spectroscopy at the end of Josephson junctions realized on a heterostructure consisting of aluminium on indium arsenide. Biasing the junction to φ ≈ π reduces the critical field at which the zero-bias peak appears, with respect to φ = 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. As well as providing experimental evidence of phase-tuned topological superconductivity, our devices are compatible with superconducting quantum electrodynamics architectures11 and are scalable to the complex geometries needed for topological quantum computing9,12,13.
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
SN - 0028-0836
VL - 569
SP - 89
EP - 92
JO - Nature
JF - Nature
ER -