Strain-induced Berry phase in chiral superconductors

Abstract

We study the topology of the order parameter in the intermediate phase between the superconducting and time-reversal symmetry breaking transitions of a $p_x+i{p}_y$ superconductor under strain. The application of in-plane strain reduces the underlying crystal symmetry and lifts the degeneracy of the critical temperature between the $p_x$ and $p_y$ orbitals, resulting in a Dirac cone structure in the thermodynamic phase diagram. When the strain is varied adiabatically along a closed path enclosing the Dirac cone, the order parameter acquires a Berry phase of $\pi$, which originates from a half rotation of the superconducting gap function. This half rotation leaves a topological signature in the superfluid stiffness tensor, making it directly observable through the geometry of vortices and the upper critical field.

main text: 7 pages, 5 figures; supplemental material: 11 pages, 1 figure

References in corpus (21)

• Non-abelian statistics of half-quantum vortices in p-wave superconductors
• Superconductivity in Iron Compounds
• Odd-Parity Topological Superconductors: Theory and Application to Cu${}_x$Bi${}_2$Se${}_3$
• Chiral Superconductors
• Strong Peak in $T_c$ of Sr${}_2$RuO${}_4$ Under Uniaxial Pressure
• Space dependent Fermi velocity in strained graphene
• Odd-parity topological superconductor with nematic order: Application to CuxBi2Se3
• Split superconducting and time-reversal symmetry-breaking transitions, and magnetic order in Sr${}_2$RuO${}_4$ under uniaxial stress
• Thermodynamic Evidence for a Two-Component Superconducting Order Parameter in Sr${}_2$RuO${}_4$
• Ultrasound evidence for a two-component superconducting order parameter in Sr${}_2$RuO${}_4$
• A proposal for reconciling diverse experiments on the superconducting state in Sr2RuO4
• Nematic superconductivity in doped Bi2Se3 topological superconductors
• Unsplit superconducting and time reversal symmetry breaking transitions in Sr${}_2$RuO${}_4$ under hydrostatic pressure and disorder
• Chiral to Nematic Crossover in the Superconducting State of 4Hb-TaS${}_2$
• Evidence of a two-component order parameter in 4Hb-TaS2 in the Little-Parks effect
• $\mu$SR measurements on Sr${}_2$RuO${}_4$ under $⟨110⟩$ uniaxial stress
• $T_c$ and the elastocaloric effect of Sr${}_2$RuO${}_4$ under $⟨110⟩$ uniaxial stress: no indications of transition splitting
• Leggett Modes in Dirac Semimetals
• Effect of strain inhomogeneity on a chiral p-wave superconductor
• Superfluid phase transition of nanoscale-confined helium-3
• Topological Landau Theory