Space-time crystalline order of a high-critical-temperature superconductor with intrinsic Josephson junctions

TL;DR

This paper theoretically shows that the high-temperature superconductor BSCCO can naturally form a space-time crystal through Josephson junctions under periodic modulation, revealing new nonequilibrium phases in condensed matter.

Contribution

It introduces the concept of space-time crystalline order in a high-Tc superconductor with intrinsic Josephson junctions under parametric modulation, a novel theoretical prediction.

Findings

Space-time crystalline order can be induced in BSCCO via periodic modulation.

A phase diagram of spatiotemporal order parameter is established.

Proposal for a laser-modulation experiment to observe this behavior.

Abstract

We theoretically demonstrate that the high-critical-temperature superconductor Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ (BSCCO) is a natural candidate for the recently envisioned classical space-time crystal. BSCCO intrinsically forms a stack of Josephson junctions. Under a periodic parametric modulation of the Josephson critical current density, the Josephson currents develop coupled space-time crystalline order, breaking the continuous translational symmetry in both space and time. The modulation frequency and amplitude span a (nonequilibrium) phase diagram for a so-defined spatiotemporal order parameter, which displays rigid pattern formation within a particular region of the phase diagram. Based on our calculations using representative material properties, we propose a laser-modulation experiment to realize the predicted space-time crystalline behavior. Our findings bring new insight into the nature of space-time crystals and, more generally, into nonequilibrium driven condensed matter systems.