Theory and simulations of quantum glass forming liquids

Abstract

A comprehensive microscopic dynamical theory is presented for the description of quantum fluids as they transform into glasses. The theory is based on a quantum extension of mode-coupling theory. Novel effects are predicted, such as reentrant behavior of dynamical relaxation times. These predictions are supported by path integral ring polymer molecular dynamics simulations. The simulations provide detailed insight into the factors that govern slow dynamics in glassy quantum fluids. Connection to other recent work on both quantum glasses as well as quantum optimization problems is presented.

On static triplet structures in fluids with quantum behavior

“…Apart from its intrinsic interest, this is an effort expected to ease the way toward the generalization and further applications of theoretical approaches aimed at the study of current quantum condensed matter problems (e.g., mode-coupling theories of glass-forming liquids). 31,40,73,[82][83][84][85] …”

Direct simulation of proton-coupled electron transfer across multiple regimes

“…23,24 It provides a classical molecular dynamics model for the real-time evolution of a quantum mechanical system that rigorously preserves detailed balance and samples the quantum Boltzmann distribution. [24][25][26] The RPMD method has been previously employed to investigate a wide range of quantized reactive and dynamical processes, [27][28][29][30][31][32][33][34][35][36][37][38][39][40] ranging from gas-phase triatomic reactions 27 to enzyme-catalyzed hydrogen tunneling. 28 We have demonstrated that RPMD simulations can be extended to accurately and efficiently describe coupled electronic and nuclear dynamics in condensed-phase systems, including excess electron diffusion, 31 injection, 32 and reactive transfer.…”

Observation of crystallization slowdown in supercooled parahydrogen and orthodeuterium quantum liquid mixtures

“…However, diverse drawbacks such as polydispersity and sedimentation often make the experimental data from these systems difficult to interpret [8,9]. Accessing the details of the crystallization process in simple atomic and molecular counterparts, on the other hand, remains an experimental challenge due to relevant time scales that are orders of magnitude shorter.Theoretical studies have shown that the inclusion of quantum effects adds a further degree of complexity in the behavior of supercooled liquids, leading to novel exotic phenomena such as superfluidity [10,11] or enhanced dynamical slowing down [12][13][14]. Yet again, the difficulties in supercooling a quantum liquid to very low temperatures have so far precluded possible experimental studies of the interplay of quantum effects and structural transformations in nonequilibrium bulk liquids.…”

“…Theoretical studies have shown that the inclusion of quantum effects adds a further degree of complexity in the behavior of supercooled liquids, leading to novel exotic phenomena such as superfluidity [10,11] or enhanced dynamical slowing down [12][13][14]. Yet again, the difficulties in supercooling a quantum liquid to very low temperatures have so far precluded possible experimental studies of the interplay of quantum effects and structural transformations in nonequilibrium bulk liquids.…”