Quantum simulation methods based on electronic-structure theory are deemed unfit to cope with atomic heat transport within the Green–Kubo formalism, because quantum-mechanical energy densities and currents are inherently ill-defined at the atomic scale. We show that, although this difficulty would also affect classical simulations, thermal conductivity is indeed insensitive to such ill-definedness by virtue of a kind of gauge invariance resulting from energy extensivity and conservation. On the basis of these findings, we derive an expression for the adiabatic energy flux from density-functional theory, which allows heat transport to be simulated using ab initio equilibrium molecular dynamics. Our methodology is demonstrated by comparing its predictions to those of classical equilibrium and ab initio non-equilibrium (Müller–Plathe) simulations for a liquid-argon model, and by applying it to heavy water at ambient conditions. © 2016 Macmillan Publishers Limited.

Microscopic theory and quantum simulation of atomic heat transport / Marcolongo, A.; Umari, P.; Baroni, S.. - In: NATURE PHYSICS. - ISSN 1745-2473. - 12:1(2016), pp. 80-84. [10.1038/nphys3509]

Microscopic theory and quantum simulation of atomic heat transport

Marcolongo, A.;Baroni, S.
2016-01-01

Abstract

Quantum simulation methods based on electronic-structure theory are deemed unfit to cope with atomic heat transport within the Green–Kubo formalism, because quantum-mechanical energy densities and currents are inherently ill-defined at the atomic scale. We show that, although this difficulty would also affect classical simulations, thermal conductivity is indeed insensitive to such ill-definedness by virtue of a kind of gauge invariance resulting from energy extensivity and conservation. On the basis of these findings, we derive an expression for the adiabatic energy flux from density-functional theory, which allows heat transport to be simulated using ab initio equilibrium molecular dynamics. Our methodology is demonstrated by comparing its predictions to those of classical equilibrium and ab initio non-equilibrium (Müller–Plathe) simulations for a liquid-argon model, and by applying it to heavy water at ambient conditions. © 2016 Macmillan Publishers Limited.
2016
12
1
80
84
http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3509.html
https://arxiv.org/abs/1503.04188
https://arxiv.org/abs/1503.04188
Marcolongo, A.; Umari, P.; Baroni, S.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11767/11390
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