The classical limit of quantum transport

R. Brout

Didrik Palmqvist, Ludovico Tesser, Janine Splettstoesser

We analyze the precision of generic currents in a multiterminal quantum-transport setting. Employing scattering theory, we show that the precision of such currents is limited by a function of the particle-current noise that can be interpreted as the activity in the classical limit. We thereby establish a kinetic uncertainty relation for quantum transport. In the full quantum limit, we find precision bounds with modified activity constraints depending on whether the system is fermionic or bosonic. We expect these bounds to be suitable as guidelines for any transport process aiming at high precision.

David K. Ferry

J. F. Poyatos, Gonzalo G. de Polavieja

A procedure to enhance the quantum--classical correspondence even in situations far from the classical limit is proposed. It is based on controlling the quantum transport between classical regions using the capability to synthesize arbitrary motional states in ion traps. Quantum barriers and passages to transport can be created selecting the relevant frequencies. This technique is then applied to stabilize the quantum motion onto classical structures or alter the dynamical tunneling in nonintegrable systems.

David K. Ferry, Mihail Nedjalkov

X. P. Xu, Wei Li, Feng Liu

We study the coherent exciton transport on Apollonian networks generated by simple iterative rules. The coherent exciton dynamics is modeled by continuous-time quantum walks and we calculate the transition probabilities between two nodes of the networks. We find that the transport depends on the initial nodes of the excitation. For networks up to the second generation the coherent transport shows perfect recurrences when the initial excitation starts at the central node. For networks of higher generation, the transport only shows partial revivals. Moreover, we find that the excitation is most likely to be found at the initial nodes while the coherent transport to other nodes has a very low probability. In the long time limit, the transition probabilities show characteristic patterns with identical values of limiting probabilities. Finally, the dynamics of quantum transport are compared with the classical transport modeled by continuous-time random walks.