Higher-order and fractional discrete time crystals in Floquet-driven Rydberg atoms

TL;DR

This paper reports an experimental method to observe higher-order and fractional discrete time crystals in Floquet-driven Rydberg gases, revealing multiple DTCs with various integer and fractional periods, advancing understanding of non-equilibrium quantum phases.

Contribution

The authors experimentally demonstrate higher-order and fractional DTCs in Rydberg atomic gases, a significant step beyond previous theoretical studies.

Findings

Multiple integer n-DTCs observed with n=2, 3, 4, and up to 14.

Fractional n-DTCs with non-integer n values beyond the integers.

Transitions between adjacent integer DTCs and fractional DTCs explored.

Abstract

Higher-order and fractional discrete time crystals (DTCs) are exotic phases of matter where the discrete time translation symmetry is broken into higher-order and non-integer category. Generation of these unique DTCs has been widely studied theoretically in different systems. However, no current experimental methods can probe these higher-order and fractional DTCs in any quantum many-body systems. We demonstrate an experimental approach to observe higher-order and fractional DTCs in Floquet-driven Rydberg atomic gases. We have discovered multiple $n$-DTCs with integer values of $n$ = 2, 3, and 4, and others ranging up to 14, along with fractional $n$-DTCs with $n$ values beyond the integers. The system response can transition between adjacent integer DTCs, during which the fractional DTCs are investigated. Study of higher-order and fractional DTCs expands fundamental knowledge of non-equilibrium dynamics and is promising for discovery of more complex temporal symmetries beyond the single discrete time translation symmetry.