About Chemical Modifications of Finite Dimensional QED Models

Suggestion of modifications of finite-dimensional quantum-electrodynamic (QED) models are proposed for interpreting chemical reactions in terms of artificial atoms and molecules on quantum dots placed in optical cavities. Moving both photons and atoms is possible between the cavities. Super dark states of diatomic systems are described, in which the motion of atoms between cavities is impossible due to quantum interference. Chemical processes with two level atoms and three level atoms with lambda spectrum are schematically modeled by solving the single quantum master equation with the Lindblad operators of photon leakage from the cavity and influx into it; association and dissociation reactions then differ only in the initial states. An example is given of the optical interpretation of the transition of an electron from atom to atom in terms of the multilevel Tavis-Cummings-Hubbard model with an estimate of the accuracy. Polyatomic chemical reactions are too complex for accurate modeling. Our method of rough interpretation helps to obtain their long-term results, for example, the form of stationary states of reagents, such as dark and super dark states.

Suppression of shot noise in a spin–orbit coupled quantum dot

We study theoretically the transport properties of electrons in a quantum dot system with spin–orbit coupling. By using the quantum master equation approach, the shot noise and skewness of the transport electrons are calculated. We obtain super-Poisson noise behaviour by investigating the full counting statistics of the transport system. We discover super-Poisson behaviour is more obvious with the spin polarization increasing. More importantly, we discover the suppression of shot noise induced by spin–orbit coupling. The value of shot noise is gradually decreasing when spin–orbit coupling strength increases.

Retarded resonance Casimir–Polder interaction of a uniformly rotating two-atom system

We consider a two-atom system uniformly moving through a circular ring at an ultra-relativistic speed and weakly interacting with the common quantum fields. Two kinds of fields are introduced here: a massive free scalar field and electromagnetic (EM) vector fields. The vacuum fluctuations of the quantum fields give rise to the resonance Casimir–Polder interaction (RCPI) in the system. Using the quantum master equation formalism, we calculate the second-order energy shift of the entangled states of the system. We find two major aspects of RCPI in a circular trajectory. The first one is the presence of the centripetal acceleration, which gives rise to non-thermality in the system, and secondly, due to the interaction with the above fields, the energy shift for RCPI is retarded in comparison with the massless scalar field. The retardation effect can die out by decreasing the centripetal acceleration and increasing the Zeeman frequency of the atoms. We also show that this phenomenon can be observed via the polarization transfer technique. The coherence time for the polarization transfer is calculated, which is different for the different fields.

Generation of Werner-like states via a two-qubit system plunged in a thermal reservoir and their application in solving binary classification problems

We present a theoretical scheme for the generation of stationary entangled states. To achieve the purpose we consider an open quantum system consisting of a two-qubit plunged in a thermal bath, as the source of dissipation, and then analytically solve the corresponding quantum master equation. We generate two classes of stationary entangled states including the Werner-like and maximally entangled mixed states. In this regard, since the solution of the system depends on its initial state, we can manipulate it and construct robust Bell-like state. In the continuation, we analytically obtain the population and coherence of the considered two-qubit system and show that the residual coherence can be maintained even in the equilibrium condition. Finally, we successfully encode our two-qubit system to solve a binary classification problem. We demonstrate that, the introduced classifiers present high accuracy without requiring any iterative method. In addition, we show that the quantum based classifiers beat the classical ones.