Holographic quenches in a confined phase

Abstract

We investigate quenches of holographic theories in a confined phase, where the energy injected is insufficient to reach the deconfined phase. In such quenches, thermalization is not associated with gravitational collapse and the formation of a black hole. Nevertheless, we attempt to characterize the late-time state of this scenario. We check a number of notions of thermalization that do not require horizon formation, and find no evidence for thermalization in our chosen parameters and initial states, even in the weakest sense.We find that the post-quench behaviour of both local and nonlocal observables exhibit oscillatory behaviour rather than decaying towards equilibrium. We generally find that the response of the nonlocal observables is smoother than that of the local ones. We discuss mechanisms which generate such smoothing, as well as "beats" which appear in the time-dependence of the nonlocal operators for certain classes of quenches. When tuning the quench parameters such that the smoothing is ineffective, we are able to perform "entanglement spectroscopy", recovering the spectrum of the confined phase of the theory from the time dependence of the entanglement entropy, as well as other nonlocal observables.

Signatures of rare states and thermalization in a theory with confinement

“…The rare states in the field theory (2) are intimately related to the presence of a linearly confining potential for the domain wall excitations. We note that recent work on confined phases in holographic theories also suggests an absence of thermalization, 118 which may lead one to speculate that models with confinement in general exhibit a lack of thermalization. This is partially supported by recent results of the authors 82 that show anomalous nonequilibrium dynamics in a twodimensional model with confinement that are completely analogous to the one-dimensional problem.…”

Probing anomalous driving

“…For example, quenches exhibit interesting transient behavior before and after the quench, see, e.g., [1][2][3][4][5][6]. Holographic analyses of quenches have been studied in, for example, [7][8][9][10][11]. Likewise, periodically driven systems have received renewed interest.…”

Nonthermal States Arising from Confinement in One and Two Dimensions

“…While we have focused on Ising models in 1D and 2D, it is natural to expect that the physics of nonthermal states carries over to other theories with confinement. Recently, holographic theories with confinement have shown an absence of thermalization [61], a hallmark of the presence of nonthermal states. A natural test of this conjecture could be provided by the Schwinger model in an electric field, which has been the subject of a number of recent works [62][63][64][65][66][67] (the disordered Schwinger model has also recently been shown to display confinement driven non-ergodic behaviour [68,69]).…”