Anomalous quantum heat transport in a one-dimensional harmonic chain with random couplings.
We investigate quantum heat transport in a one-dimensional harmonic system with random couplings. In the presence of randomness, phonon modes may normally be classified as ballistic, diffusive or localized. We show that these modes can roughly be characterized by the local nearest-neighbor level spacing distribution, similarly to their electronic counterparts. We also show that the thermal conductance G(th) through the system decays rapidly with the system size (G(th) ∼ L(-α)). The exponent α strongly depends on the system size and can change from α < 1 to α > 1 with increasing system size, indicating that the system undergoes a transition from a heat conductor to a heat insulator. This result could be useful in thermal control of low-dimensional systems.
Department of Physics, Shaoxing University, Shaoxing 312000, People's Republic of China.
Yonghong
Y
Yan
Hui
H
Zhao
D000465:Algorithms; D003198:Computer Simulation; D006358:Hot Temperature; D008958:Models, Molecular; D015233:Models, Statistical; D060739:Phonons; D011789:Quantum Theory; D013814:Thermal Conductivity; D013816:Thermodynamics