TY - JOUR
T1 - Two-dimensional Josephson vortex lattice and anomalously slow decay of the Fraunhofer oscillations in a ballistic SNS junction with a warped Fermi surface
AU - Ostroukh, V. P.
AU - Baxevanis, B.
AU - Akhmerov, A. R.
AU - Beenakker, C. W J
PY - 2016/9/16
Y1 - 2016/9/16
N2 - The critical current of a Josephson junction is an oscillatory function of the enclosed magnetic flux Φ, because of quantum interference modulated with periodicity h/2e. We calculate these Fraunhofer oscillations in a two-dimensional (2D) ballistic superconductor-normal-metal-superconductor (SNS) junction. For a Fermi circle the amplitude of the oscillations decays as 1/Φ or faster. If the Fermi circle is strongly warped, as it is on a square lattice near the band center, we find that the amplitude decays slower, 1/Φ, when the magnetic length lm=/eB drops below the separation L of the NS interfaces. The crossover to the slow decay of the critical current is accompanied by the appearance of a 2D array of current vortices and antivortices in the normal region, which form a bipartite rectangular lattice with lattice constant ≃lm2/L. The 2D lattice vanishes for a circular Fermi surface, when only the usual single row of Josephson vortices remains.
AB - The critical current of a Josephson junction is an oscillatory function of the enclosed magnetic flux Φ, because of quantum interference modulated with periodicity h/2e. We calculate these Fraunhofer oscillations in a two-dimensional (2D) ballistic superconductor-normal-metal-superconductor (SNS) junction. For a Fermi circle the amplitude of the oscillations decays as 1/Φ or faster. If the Fermi circle is strongly warped, as it is on a square lattice near the band center, we find that the amplitude decays slower, 1/Φ, when the magnetic length lm=/eB drops below the separation L of the NS interfaces. The crossover to the slow decay of the critical current is accompanied by the appearance of a 2D array of current vortices and antivortices in the normal region, which form a bipartite rectangular lattice with lattice constant ≃lm2/L. The 2D lattice vanishes for a circular Fermi surface, when only the usual single row of Josephson vortices remains.
UR - http://resolver.tudelft.nl/uuid:5bf7bad8-d648-45a9-9ba5-49f595f0c966
UR - http://www.scopus.com/inward/record.url?scp=84991000997&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.94.094514
DO - 10.1103/PhysRevB.94.094514
M3 - Article
AN - SCOPUS:84991000997
SN - 1098-0121
VL - 94
SP - 1
EP - 11
JO - Physical Review B (Condensed Matter and Materials Physics)
JF - Physical Review B (Condensed Matter and Materials Physics)
IS - 9
M1 - 094514
ER -