Quantum dynamics to study quantum phase transition and heat transport

J. Phys. Chem. Lett., 11, 10, 4080–4085 (2020)

J. Chem. Phys. 147, 164112 (2017)

Phys. Rev. B 95, 214308 (2017)

Understanding non-equilibrium transport with quantum chemistry is crucial for controlling energy flow in nanoscale systems. We study thermal energy transfer in a generalized non-equilibrium spin-boson model (NESB) with non-commutative system–bath coupling operators and discover its unusual transport properties. Compared to the conventional NESB, the energy current is greatly enhanced by rotating the system–bath coupling operators. Constructive contribution to thermal rectification can be optimized when two sources of asymmetry, system–bath coupling strength and coupling operators, coexist. At the weak coupling and the adiabatic limit, the scaling dependence of energy current on the coupling strength and the system energy gap changes drastically when the coupling operators become non-commutative. These novel transport properties, arising from the pure quantum effect of non-commutative coupling operators, suggest an unvisited dimension of controlling transport in nanoscale systems and should generally appear in other non-equilibrium set-ups and driven systems.