Towards Quantum Simulation with Circular Rydberg Atoms

Abstract

The main objective of quantum simulation is an in-depth understanding of\nmany-body physics. It is important for fundamental issues (quantum phase\ntransitions, transport, . . . ) and for the development of innovative\nmaterials. Analytic approaches to many-body systems are limited and the huge\nsize of their Hilbert space makes numerical simulations on classical computers\nintractable. A quantum simulator avoids these limitations by transcribing the\nsystem of interest into another, with the same dynamics but with interaction\nparameters under control and with experimental access to all relevant\nobservables. Quantum simulation of spin systems is being explored with trapped\nions, neutral atoms and superconducting devices. We propose here a new paradigm\nfor quantum simulation of spin-1/2 arrays providing unprecedented flexibility\nand allowing one to explore domains beyond the reach of other platforms. It is\nbased on laser-trapped circular Rydberg atoms. Their long intrinsic lifetimes\ncombined with the inhibition of their microwave spontaneous emission and their\nlow sensitivity to collisions and photoionization make trapping lifetimes in\nthe minute range realistic with state-of-the-art techniques. Ultra-cold\ndefect-free circular atom chains can be prepared by a variant of the\nevaporative cooling method. This method also leads to the individual detection\nof arbitrary spin observables. The proposed simulator realizes an XXZ spin-1/2\nHamiltonian with nearest-neighbor couplings ranging from a few to tens of kHz.\nAll the model parameters can be tuned at will, making a large range of\nsimulations accessible. The system evolution can be followed over times in the\nrange of seconds, long enough to be relevant for ground-state adiabatic\npreparation and for the study of thermalization, disorder or Floquet time\ncrystals. This platform presents unrivaled features for quantum simulation.\n