Stroboscopic aliasing in long-range interacting quantum systems

TL;DR

This paper introduces a novel stroboscopic aliasing mechanism in long-range quantum spin systems, enabling the creation of arbitrary oscillation multiplets and breaking discrete time translation symmetry, with potential applications in quantum simulation.

Contribution

It reveals a new aliasing-based mechanism for generating complex oscillations in long-range interacting quantum systems, expanding the understanding of time crystal-like phenomena.

Findings

Demonstrates robustness of aliasing effects to detuning

Shows potential for engineering multi-periodic oscillations

Suggests applications in spin squeezing and entanglement

Abstract

We unveil a mechanism for generating oscillations with arbitrary multiplets of the period of a given external drive, in long-range interacting quantum many-particle spin systems. These oscillations break discrete time translation symmetry as in time crystals, but they are understood via two intertwined stroboscopic effects similar to the aliasing resulting from video taping a single fast rotating helicopter blade. The first effect is similar to a single blade appearing as multiple blades due to a frame rate that is in resonance with the frequency of the helicopter blades' rotation; the second is akin to the optical appearance of the helicopter blades moving in reverse direction. Analogously to other dynamically stabilized states in interacting quantum many-body systems, this stroboscopic aliasing is robust to detuning and excursions from a chosen set of driving parameters, and it offers a novel route for engineering dynamical $n$-tuplets in long-range quantum simulators, with potential applications to spin squeezing generation and entangled state preparation.