We consider an unexplored aspect of the mass equivalence principle in the

quantum realm, its connection with atomic stability. We show that if the

gravitational mass were different from the inertial one, a Hydrogen atom placed

in a constant gravitational field would become unstable in the long term. In

contrast, independently of the relation between the two masses, the atom does

not become ionized in an uniformly accelerated frame. This work, in the line of

# All

Inspired by the decomposition in the hybrid quantum-classical optimization

algorithm we introduced in arXiv:1902.04215, we propose here a new (fully

classical) approach to solving certain non-convex integer programs using Graver

bases. This method is well suited when (a) the constraint matrix $A$ has a

special structure so that its Graver basis can be computed systematically, (b)

several feasible solutions can also be constructed easily and (c) the objective

We study the steady state entanglement and correlations of an open system

comprised of two fermions coupling with the equilibrium or nonequilibrium

environments. We find that for equilibrium case, quantum correlations exhibit

non-monotonic behavior with the increase of temperature and quantum

entanglement dies at finite temperature. Under nonequilibrium environments, the

quantum correlations can show monotonic or non-monotonic behavior upon the

change of temperature or chemical potential bias depending on the tunneling

Great advances in precision quantum measurement have been achieved with

trapped ions and atomic gases at the lowest possible temperatures. These

successes have inspired ideas to merge the two systems. In this way one can

study the unique properties of ionic impurities inside a quantum fluid or

explore buffer gas cooling of the trapped ion quantum computer. Remarkably, in

spite of its importance, experiments with atom-ion mixtures remained firmly

confined to the classical collision regime. We report a collision energy of

The study of quantum dynamics featuring memory effects has always been a

topic of interest within the theory of open quantum system, which is concerned

about providing useful conceptual and theoretical tools for the description of

the reduced dynamics of a system interacting with an external environment.

Definitions of non-Markovian processes have been introduced trying to capture

the notion of memory effect by studying features of the quantum dynamical map

providing the evolution of the system states, or changes in the

We consider a continuous-time quantum walk on a triple graph and investigate

the influence of the side chain on the propagation in the main chain.

Calculating the interchange of the probabilities between the two parts of the

main chain, we find that a switching effect appears if there are odd number of

points on the side chain when concrete conditions between the length of the

main chain and the position of the side chain are satisfied. Whereas, such an

The realization of the strong coupling regime is requisite for implementing

quantum information tasks. Here, a method for enhancing the atom-field coupling

in highly dissipative coupled cavities is proposed. By introducing parametric

squeezing into the primary cavity which is only virtually excited under

specific parametric conditions, coupling enhancement between atom and auxiliary

cavity is realized for proper squeezing parameters. This enables the system to

Consider a classical system, which is in the state described by probability

distribution $p$ or $q$, and embed these classical informations into quantum

system by a physical map $\Gamma$, $\rho=\Gamma(p)$ and $\sigma=\Gamma(q)$.

Intuitively, the pair $\{p_{\rho}^{M},p_{\sigma}^{M}\}$ of the distributions of

the data of the measurement $M$ on the pair $\{\rho,\sigma\}$ should contain

strictly less information than the pair $\{p,q\}$ provided the pair

$\{\rho,\sigma\}$ is non-commutative. Indeed, this statement had been shown if