Observation of many-body dynamics in long-range tunneling after a quantum quench

Abstract

Quantum tunneling is at the heart of many low-temperature phenomena. In strongly correlated lattice systems, tunneling is responsible for inducing effective interactions, and long-range tunneling substantially alters many-body properties in and out of equilibrium. We observe resonantly enhanced long-range quantum tunneling in one-dimensional Mott-insulating Hubbard chains that are suddenly quenched into a tilted configuration. Higher-order tunneling processes over up to five lattice sites are observed as resonances in the number of doubly occupied sites when the tilt per site is tuned to integer fractions of the Mott gap. This forms a basis for a controlled study of many-body dynamics driven by higher-order tunneling and demonstrates that when some degrees of freedom are frozen out, phenomena that are driven by small-amplitude tunneling terms can still be observed.

Keldysh field theory for driven open quantum systems

“…It comes along with a very weak coupling of the system to the environment, such that the dynamics can often be seen as isolated on relevant time scales for typical measurements of static, equilibrium correlations. However, more and more experiments start to investigate the realm of non-equilibrium phenomena with cold atoms, e.g., by letting systems prepared in a non-equilibrium initial condition relax in time towards a steady state [37,39,[163][164][165]. With these experiments, time scales are reached, for which the dissipative coupling to the environment becomes visible in experimental observables.…”

Prethermalization and thermalization of a quenched interacting Luttinger liquid

“…Concerning the relevance of the interacting Luttinger model, before closing the section, we would like to mention that only recently pioneering experiments in ultra-cold gases both in and out of equilibrium explored the transient and prethermalization dynamics of systems [16][17][18][19][20][21][22][23][24][25][26][68][69][70] effectively described by a quadratic Luttinger model, the bosonic theory of the Hamiltonian in Eq. (2.2).…”

“…The increasing number of cold atom experiments performed under out of equilibrium conditions [14][15][16][17][18][19][20][21][22][23] has driven significant interest in the theoretical understanding of the non-equilibrium dynamics in quantum many-body systems. Importantly, these experiments share a remarkable isolation from the environment, thereby probing the purely coherent unitary time evolution on the experimentally relevant time scales.…”

Bloch oscillations and quench dynamics of interacting bosons in an optical lattice

“…Our analysis provides a unified theory for interacting BO which treats all regimes, and makes predictions that should be within reach of future experiments. Experiments in the strong-F regime have recently been performed by F. Meinert et al [26].…”

“…We are also interested in the prospects for using Bloch oscillations of cold atoms for precision measurement of g. Most experiments have previously focused on the meanfield regime [15,16,19], where up to 20000 BO have been observed, although very recently experiments [26] have operated within the strongly-correlated, deep lattice regime. We present estimates for the bounds on the residual harmonic trapping and finite tunneling that should allow observations of up to 50000 Bloch oscillations.…”