arXiv subjects

M. Endres

Publications and source records attributed to M. Endres.

4 recordsLinked to original sources

arXiv2016

Scrambling and thermalization in a diffusive quantum many-body system

Out-of-time ordered (OTO) correlation functions describe scrambling of information in correlated quantum matter. They are of particular interest in incoherent quantum systems lacking well defined quasi-particles. Thus far, it is largely elusive how OTO correlators spread in incoherent systems with diffusive transport governed by a few globally conserved quantities. Here, we study the dynamical response of such a system using high-performance matrix-product-operator techniques. Specifically, we consider the non-integrable, one-dimensional Bose-Hubbard model in the incoherent high-temperature regime. Our system exhibits diffusive dynamics in time-ordered correlators of globally conserved quantities, whereas OTO correlators display a ballistic, light-cone spreading of quantum information. The slowest process in the global thermalization of the system is thus diffusive, yet information spreading is not inhibited by such slow dynamics. We furthermore develop an experimentally feasible protocol to overcome some challenges faced by existing proposals and to probe time-ordered and OTO correlation functions. Our study opens new avenues for both the theoretical and experimental exploration of thermalization and information scrambling dynamics.

cond-mat.quant-gas↗

arXiv2015

Commissioning of the PRIOR proton microscope

Recently a new high energy proton microscopy facility PRIOR (Proton Microscope for FAIR) has been designed, constructed and successfully commissioned at GSI Helmholtzzentrum f\"ur Schwerionenforschung (Darmstadt, Germany). As a result of the experiments with 3.5-4.5 GeV proton beams delivered by the heavy ion synchrotron SIS-18 of GSI, 30 um spatial and 10 ns temporal resolutions of the proton microscope have been demostrated. A new pulsed power setup for studying properties of matter under extremes has been developed for the dynamic commissioning of the PRIOR facility. This paper describes the PRIOR setup as well as the results of the first static and dynamic proton radiography experiments performed at GSI.

physics.ins-det↗

arXiv2011

Observation of Correlated Particle-Hole Pairs and String Order in Low-Dimensional Mott Insulators

Quantum phases of matter are characterized by the underlying correlations of the many-body system. Although this is typically captured by a local order parameter, it has been shown that a broad class of many-body systems possesses a hidden non-local order. In the case of bosonic Mott insulators, the ground state properties are governed by quantum fluctuations in the form of correlated particle-hole pairs that lead to the emergence of a non-local string order in one dimension. Using high-resolution imaging of low-dimensional quantum gases in an optical lattice, we directly detect these pairs with single-site and single-particle sensitivity and observe string order in the one-dimensional case.

cond-mat.quant-gas↗

arXiv1998

Emergence of superconducting gap features in Bi2Sr2CaCu2O8+delta single crystals from intrinsic c-axis interlayer tunneling

Static and dynamic transport measurements on stacks of intrinsic Josephson junctions on Bi2Sr2CaCu2O8+delta single crystals, near to optimal doping, are presented. The zero bias minimum in dynamic conductance is consistent with a normal state pseudo-gap. At Tc, a critical current develops simultaneously with new features consistent with a gap in the superconducting density states at an already well-established energy. The lack of thermal broadening and the small scale of the features force us to conclude a high degree of coherent interlayer tunneling in both the superconducting and normal states.

cond-mat.supr-con↗