Order parameter symmetry and mode coupling effects at dirty superconducting quantum phase transitions

Abstract

We derive an order-parameter field theory for a quantum phase transition between a disordered metal and an exotic (non-s-wave) superconductor. Mode coupling effects between the order parameter and other fermionic soft modes lead to an effective long-range interaction between the anomalous density fluctuations which is reflected in singularities in the free energy functional. However, this long-range interaction is not strong enough to suppress disorder fluctuations. The asymptotic critical region is characterized by run-away flow to large disorder. For weak coupling, this asymptotic region is very narrow. It is preempted by a wide crossover regime with mean-field critical behavior and, in the p-wave case, logarithmic corrections to scaling in all dimensions.

final version as published

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Cited by in corpus (5)

• Influence of Generic Scale Invariance on Classical and Quantum Phase Transitions
• Infinite-randomness quantum critical points induced by dissipation
• Resilience of Majorana Fermions in the face of Disorder
• Effect of weak disorder on the phase competition in iron pnictides
• Superconducting transition in disordered granular superconductors in magnetic fields