Multicritical behavior in dissipative Ising models

TL;DR

This paper investigates the complex phase behavior of a dissipative Ising model in a transverse field, revealing a multicritical point and developing a field theory to understand its universality class, with potential experimental realization.

Contribution

It introduces a variational and field-theoretical analysis of dissipative Ising models, highlighting a new multicritical point and its universality class, along with experimental proposals.

Findings

Discovery of a multicritical point with a different universality class

Development of a dissipative Ginzburg-Landau theory

Proposal for experimental realization with ultracold Rydberg gases

Abstract

We analyze theoretically the many-body dynamics of a dissipative Ising model in a transverse field using a variational approach. We find that the steady state phase diagram is substantially modified compared to its equilibrium counterpart, including the appearance of a multicritical point belonging to a different universality class. Building on our variational analysis, we establish a field-theoretical treatment corresponding to a dissipative variant of a Ginzburg-Landau theory, which allows us to compute the upper critical dimension of the system. Finally, we present a possible experimental realization of the dissipative Ising model using ultracold Rydberg gases.