Quantum rate theory: basic methods

Jiřı́ Pokorný, Tsu-Ming Wu

Sture Nordholm, George B. Bacskay

The aim of this work is to provide a new conceptually and practically useful method of obtaining the time development and particularly the decay of quantum states initially localized on a domain with dynamically open boundaries. A projection operator derivation and a Markoffian approximation is used to obtain an effective Hamiltonian capable of describing the dynamics on the open domain. The basic algebra is implemented for one dimensional systems and a series of test calculations presented which serve to verify the validity of the approximations and illustrate the accuracy of the new procedure. The absorbing boundary method developed here bears some resemblance to the optical potential methods and the Feshbach projection scheme used in scattering theory and can be applied to dissociation and ionization processes as well as to scattering processes.

Lingyu Tan, Re-Bing Wu, Dewei Li +1 more

Quantum identification is a basic step for many quantum technologies. In this paper, we propose an inverse-system method to identify the damping rate function of a non-Markovian single-qubit system. Based on the time-convolution-less master equation, and using measured time traces of observables, the inverse-system method can extract the unknown damping rate function. For a computational singularity problem, we avoid it by switching between the two measured observebles. The effectiveness of our method is demonstrated in a numerical simulation.

Chen Peng, Cai You-Xun, Xiao-Fei Cai +2 more

Targeting the quantum communication network based on entangled states, a network model is proposed. According to the model, the quantum channel establishing rate of basic links is then analyzed. For different quantum channel establishment methods, the quantum channel establishing rates of long relay links are also analyzed. Then the quantum channel establishing rates corresponding to the point-by-point method and segmentation method are calculated. Finally, the quantum channel establishing rate between two arbitrary points in a large-scale quantum entanglement communication network is analyzed based on the percolation model. The quantum channel establishing rate in a quantum communication network of n nodes is Ω (1/n).

Brittany L. Hyland, Craig C. Martens