Charge $4e$ superconductivity from pair density wave order in certain high temperature superconductors

Abstract

A number of spectacular experimental anomalies\cite{li-2007,fujita-2005} have recently been discovered in certain cuprates, notably {\LBCO} and {\LNSCO}, which exhibit unidirectional spin and charge order (known as ``stripe order''). We have recently proposed to interpret these observations as evidence for a novel ``striped superconducting'' state, in which the superconducting order parameter is modulated in space, such that its average is precisely zero. Here, we show that thermal melting of the striped superconducting state can lead to a number of unusual phases, of which the most novel is a charge $4e$ superconducting state, with a corresponding fractional flux quantum $hc/4e$. These are never-before observed states of matter, and ones, moreover, that cannot arise from the conventional Bardeen-Cooper-Schrieffer (BCS) mechanism. Thus, direct confirmation of their existence, even in a small subset of the cuprates, could have much broader implications for our understanding of high temperature superconductivity. We propose experiments to observe fractional flux quantization, which thereby could confirm the existence of these states.

5 pages, 2 figures; new version in Nature Physics format with a discussion of the effective Josephson coupling J2 and minor changes. Mildly edited abstract. v3: corrected version

References in corpus (8)

• Two-Dimensional Superconducting Fluctuations in Stripe-Ordered La(1.875)Ba(0.125)CuO(4)
• Striped superconductors: How the cuprates intertwine spin, charge and superconducting orders
• Dynamical layer decoupling in a stripe-ordered, high T_c superconductor
• Dislocations and vortices in pair density wave superconductors
• Evidence for unusual superconducting correlations coexisting with stripe order in La(1.875)Ba(0.125)CuO(4)
• Competing orders in one dimensional spin 3/2 fermionic systems
• Theory of the striped superconductor
• Spectral signatures of modulated d-wave superconducting phases

Cited by in corpus (1)

• Striped superconductors: How the cuprates intertwine spin, charge and superconducting orders