1. Higher-order and fractional discrete time crystals in clean long-range interacting systems
- Author
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Pizzi, Andrea, Knolle, Johannes, Nunnenkamp, Andreas, Pizzi, Andrea [0000-0002-6714-7360], Knolle, Johannes [0000-0002-0956-2419], Nunnenkamp, Andreas [0000-0003-2390-7636], and Apollo - University of Cambridge Repository
- Subjects
Science ,General Physics and Astronomy ,FOS: Physical sciences ,Quantum mechanics ,General Biochemistry, Genetics and Molecular Biology ,Condensed Matter - Strongly Correlated Electrons ,quant-ph ,639/766/119/2795 ,639/766/483/1139 ,cond-mat.dis-nn ,Quantum Physics ,Strongly Correlated Electrons (cond-mat.str-el) ,article ,General Chemistry ,Disordered Systems and Neural Networks (cond-mat.dis-nn) ,Condensed Matter - Disordered Systems and Neural Networks ,Condensed Matter - Other Condensed Matter ,Phase transitions and critical phenomena ,Quantum Gases (cond-mat.quant-gas) ,cond-mat.other ,cond-mat.str-el ,Quantum Physics (quant-ph) ,Condensed Matter - Quantum Gases ,cond-mat.quant-gas ,Other Condensed Matter (cond-mat.other) - Abstract
Discrete time crystals are periodically driven systems characterized by a response with periodicity $nT$, with $T$ the period of the drive and $n>1$. Typically, $n$ is an integer and bounded from above by the dimension of the local (or single particle) Hilbert space, the most prominent example being spin-$1/2$ systems with $n$ restricted to $2$. Here we show that a clean spin-$1/2$ system in the presence of long-range interactions and transverse field can sustain a huge variety of different `higher-order' discrete time crystals with integer and, surprisingly, even fractional $n > 2$. We characterize these (arguably prethermal) non-equilibrium phases of matter thoroughly using a combination of exact diagonalization, semiclassical methods, and spin-wave approximations, which enable us to establish their stability in the presence of competing long- and short-range interactions. Remarkably, these phases emerge in a model with continous driving and time-independent interactions, convenient for experimental implementations with ultracold atoms or trapped ions., 6+6 pages, 4+2 figures
- Published
- 2021