skip to primary navigationskip to content

MBL in an Open Quantum System

last modified Mar 22, 2017 11:04 AM
Our paper on Signatures of Many-Body Localization in a Controlled Open Quantum System has been published in PRX.

The behavior of an isolated quantum system follows one of two distinct paradigms. It can approach a thermal equilibrium state, where any initial quantum correlations spread throughout the system, rendering the system effectively classical. Alternatively, in the presence of disorder, a system can be what is known as “many-body localized” (MBL). This regime has recently received a lot of attention because here some quantum coherences remain local up to infinite times. However, experimental investigation of this novel state is complicated by unavoidable interference from the environment, which acts as a source of fluctuations (a “bath”) that eventually thermalizes the system. We have developed a method to implement a controllable bath and present a systematic study of its effects on a MBL system.

In our experiment, we illuminate a charge-density pattern in an ensemble of ultracold potassium atoms (the MBL system) with nearly resonant light, and we investigate the system’s response. Here, the light intensity controls the coupling to the bath, and the charge-density pattern decays as a stretched exponential with a linearly dependent rate. Furthermore, we find that the susceptibility of the MBL system to the photon bath strongly increases when approaching the MBL transition, which is analogous to the effects of finite temperatures in the vicinity of a quantum phase transition.

Using control over the bath, our study is a first step toward extrapolating the behavior of truly isolated MBL systems from experimental measurements. The method for implementing a controllable photon bath also has applications in a variety of experiments on cold atoms, both within and outside of the context of MBL.

Read the paper at (Open access):


RSS Feed Latest news


May 16, 2018

We achieved Bose-Eintein condensation of K39 atoms.

Lecture course on Quantum Simulations

Jan 19, 2018

Today our new lecture course on Quantum Simulations starts in Cambridge for the first time

Slow Dynamics near the Many-Body Localization Transition

Dec 31, 2017

We could observe the (critical) slowing down of the relaxation dynamics close to the MBL transition and our results were now published in PRL (1D) and PRX (2D).

Floquet Heating in PRL

Nov 17, 2017

Our latest work on Interaction Dependent Heating and Atom Loss in a Periodically Driven Optical Lattice has been published as an Editor's suggestion in PRL

Proceeding on MBL published by Royal Society

Nov 09, 2017

The proceedings of our Royal Society meeting on the Breakdown of ergodicity in quantum systems has been published in the Philosophical Transactions of the Royal Society and contains many excellent reviews on various aspects of Many-body localization (MBL).