2016/01/27 by M. Marcuzzi, Matteo Marcuzzi, Michael Buchhold +5
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Classical limit #Cold Atom Physics and Bose-Einstein Condensates #Critical exponent #Directed percolation #Non-equilibrium thermodynamics #Percolation (cognitive psychology) #Phase transition #Physics #Quantum #Quantum critical point #Quantum fluctuation #Quantum many-body systems #Quantum mechanics #Quantum phase transition #Rydberg formula #Statistical physics #cond-mat.stat-mech #physics.atom-ph
paper · pdf · doi:10.1103/physrevlett.116.245701
published as Phys. Rev. Lett. 116, 245701 (2016) · 9 pages, 2 figures
arxiv created 2016/01/27 · openalex publication_date 2016/06/17 · arxiv updated 2016/06/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Stochastic processes with absorbing states feature examples of nonequilibrium universal phenomena. While the classical regime has been thoroughly investigated in the past, relatively little is known about the behavior of these nonequilibrium systems in the presence of quantum fluctuations. Here, we theoretically address such a scenario in an open quantum spin model which, in its classical limit, undergoes a directed percolation phase transition. By mapping the problem to a nonequilibrium field theory, we show that the introduction of quantum fluctuations stemming from coherent, rather than statistical, spin flips alters the nature of the transition such that it becomes first order. In the intermediate regime, where classical and quantum dynamics compete on equal terms, we highlight the presence of a bicritical point with universal features different from the directed percolation class in a low dimension. We finally propose how this physics could be explored within gases of interacting atoms excited to Rydberg states.