Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Fermion-parity anomaly of the critical supercurrent in the quantum spin-Hall effect
AU - Beenakker, C. W. J.
AU - Pikulin, D I
AU - Hyart, T
AU - Schomerus, Henning
AU - Dahlhaus, J P
PY - 2013/1/2
Y1 - 2013/1/2
N2 - The helical edge state of a quantum spin-Hall insulator can carry a supercurrent in equilibrium between two superconducting electrodes (separation L, coherence length xi). We calculate the maximum (critical) current Ic that can flow without dissipation along a single edge, going beyond the short-junction restriction L << xi of earlier work, and find a dependence on the fermion parity of the ground state when L becomes larger than xi. Fermion-parity conservation doubles the critical current in the low-temperature, longjunction limit, while for a short junction Ic is the same with or without parity constraints. This provides a phase-insensitive, dc signature of the 4pi-periodic Josephson effect.
AB - The helical edge state of a quantum spin-Hall insulator can carry a supercurrent in equilibrium between two superconducting electrodes (separation L, coherence length xi). We calculate the maximum (critical) current Ic that can flow without dissipation along a single edge, going beyond the short-junction restriction L << xi of earlier work, and find a dependence on the fermion parity of the ground state when L becomes larger than xi. Fermion-parity conservation doubles the critical current in the low-temperature, longjunction limit, while for a short junction Ic is the same with or without parity constraints. This provides a phase-insensitive, dc signature of the 4pi-periodic Josephson effect.
UR - http://www.scopus.com/inward/record.url?scp=84871776561&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.110.017003
DO - 10.1103/PhysRevLett.110.017003
M3 - Journal article
AN - SCOPUS:84871776561
VL - 110
JO - Physical review letters
JF - Physical review letters
SN - 1079-7114
IS - 1
M1 - 017003
ER -