Dragana Popovic (Florida State University)
Mitchell Institute for Fundamental Physics & Astronomy
College Station, Texas 77843
Understanding the dynamics of isolated disordered systems and its dependence on the range of interactions has been attracting a lot of research attention in recent years, but many questions remain open, especially in two spatial dimensions. At the same time, experiments have been limited mostly to those on synthetic quantum matter, such as ultracold atoms in optical lattices and superconducting qubits. However, observing the absence of thermalization and signatures of many-body localization (MBL) in real, solid-state materials has been a challenge. This talk will describe experimental studies of nonequilibrium dynamics in a strongly disordered, 2D electron system with a very weak thermal coupling to the environment. We find that reducing the range of the Coulomb interaction has practically no effect on the dc transport, but there is a striking difference in the dynamics. While the dynamics is glassy in the long-range case, in the case of a screened Coulomb interaction the thermalization is anomalously slow and strongly sensitive to thermal coupling to the environment, consistent with the proximity to a MBL phase. This direct observation of the MBL-like, prethermal regime in an electronic system thus clarifies the effects of the interaction range on the fate of glassy dynamics and MBL in 2D. By establishing a new, versatile solid-state platform for the study of MBL, our work also opens new possibilities for further investigations, such as noise measurements as a probe of ergodicity breaking and many-body entanglement.