Restoration of the magnetic hc/e-periodicity in unconventional superconductors

Abstract

We consider the energy of the filled quasiparticle's Fermi sea of a macroscopic superconducting ring threaded by an hc/2e-vortex, when the material of the ring is of an unconventional pairing symmetry. The energy relative to the one for the hc/e-vortex configuration is finite, positive, and inversely proportional to ring's inner radius. We argue that the existence of this energy in unconventional superconductors removes the commonly assumed degeneracy between the odd and the even vortices, with the loss of the concomitant hc/2e periodicity in external magnetic field as a consequence. This macroscopic quantum effect should be observable in nanosized unconventional superconductors with a small phase stiffness, such as deeply underdoped YBCO with Tc < 5K.

4 RevTex pages, 2 figures, published version

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Cited by in corpus (10)

• Emergence of $h/e$-period oscillations in the critical temperature of small superconducting rings threaded by magnetic flux
• Little-Parks effect in single YBaCuO sub-micron rings
• Crossover from hc/e to hc/2e current oscillations in rings of s-wave superconductors
• Flux Periodicities in Loops of Nodal Superconductors
• Tunable quantum interferometer for correlated moiré electrons
• Entanglement entropy as a witness of the Aharonov-Bohm effect in QFT
• Vortex structure in a $d$-wave superconductor obtained by a confinement transition from the pseudogap metal
• Theory of the Little-Parks effect in spin-triplet superconductors
• Zero modes and index theorems for non-Hermitian Dirac fermions
• Quantum information measures and their applications in quantum field theory