Vortex core order and field-driven phase coexistence in the attractive Hubbard model

Abstract

Superconductivity occurs in the proximity of other competing orders in a wide variety of materials. Such competing phases may reveal themselves when superconductivity is locally suppressed by a magnetic field in the core of a vortex. We explore the competition between superconductivity and charge density wave order in the attractive Hubbard model on a square lattice. Using Bogoliubov-deGennes mean field theory, we study how vortex structures form and evolve as the magnetic flux is tuned. Each vortex seeds a CDW region whose size is determined by the energy cost of the competing phase. The vortices form a lattice whose lattice parameter shrinks with increasing flux. Eventually, their charge-ordered vortex cores overlap, leading to a field-driven coexistence phase exhibiting both macroscopic charge order and superconductivity -- a `supersolid'. Ultimately, superconductivity disappears via a first-order phase transition into a purely charge ordered state. We construct a phase diagram containing these multiple ordered states, using $t^{\prime }$, the next-nearest neighbour hopping, to tune the competition between phases.

5 pages + 3 pages of supplementary materials, 9 figures

References in corpus (6)

• Direct observation of competition between superconductivity and charge density wave order in YBa2Cu3Oy
• Supersolid hardcore bosons on the triangular lattice
• Dimensional Crossover of Charge-Density Wave Correlations in the Cuprates
• Collective modes and superflow instabilities of strongly correlated Fermi superfluids
• Stability of Superflow for Ultracold Fermions in Optical Lattices
• Transverse thermoelectric transport in a model of many competing order parameters

Cited by in corpus (7)

• The phase diagram of the underdoped cuprates at high magnetic field
• Intervortex forces in competing-order superconductors
• Impurity induced phase competition and supersolidity
• Skyrmion-like textures in superconductors with competing order
• First Order Topological Phase Transitions and Disorder Induced Majorana Modes in Interacting Fermion Chains
• Vortex core ordering in Abrikosov lattices
• The attractive Hubbard model as an $SO(3)$ system of competing phases: supersolid order and its thermal melting