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We describe a many-body theory for interlayer dispersion forces between

weakly disordered atomically-thin crystals and numerically investigate the role

of disorder for different layer-separation distances and for different

densities of optically-induced electrons and holes. In contrast to the common

wisdom that disorder tends to enhance the importance of Coulomb interactions in

Fermi liquids, we find that short-range disorder tends to weaken interlayer

dispersion forces. We demonstrate that disorder alters the scaling laws of

In the rapidly growing area of quantum information, the Deutsch algorithm is

ubiquitous and, in most cases, the first one to be introduced to any student of

this relatively new field of research. The reason for this historical relevance

stems from the fact that, although extremely simple, the algorithm conveys all

the main features of more complex quantum computations. In spite of its

simplicity, the uncountable experimental realizations of the algorithm in a

The electronic Hong-Ou-Mandel interferometer in the integer quantum Hall

regime is an ideal system to probe the building up of quantum correlations

between charge carriers and it has been proposed as a viable platform for

quantum computing gates. Using a parallel implementation of the split-step

Fourier method, we simulated the antibunching of two interacting fermionic wave

packets impinging on a quantum point contact. Numerical results of the exact

approach are compared with a simplified theoretical model based on

We show that an array of qubits embedded in a waveguide can emit entangled

pairs of microwave photon beams. The quadratures obtained from a homodyne

detection of these outputs beams form a pair of correlated continuous variables

similarly to the EPR experiment. The photon pairs are produced by the decay of

plasmon-like collective excitations in the qubit array. The maximum intensity

of the resulting beams is only bounded by the number of emitters. We calculate

Quantum steering is a notion introduced by Schr\"odinger in order to capture

the essence of the Einstein-Podolsky-Rosen argument. In this paper we review

the theory of quantum steering. We present the basic definitions of steering

and local hidden state models and their relation to entanglement and Bell

nonlocality. Then, we describe the various criteria to characterize

steerability and structural results on the phenomenon. A detailed discussion is

given on the connections between steering and incompatibility of quantum

- Read more about Quantum Steering. (arXiv:1903.06663v1 [quant-ph])
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A Bell experiment can be conceptualized as a box, i.e., a process taking

classical setting variables to classical outcome variables, which has a

common-cause structure, i.e., one that can be realized by implementing local

measurements on systems that are prepared by a common-cause mechanism, with no

cause-effect relations across the wings of the experiment. For such

common-cause boxes, one can define a distinction between classical and

nonclassical in terms of what type of causal model (classical or nonclassical)

We introduce a new information theoretic measure of quantum correlations for

multiparticle systems. We use a form of multivariate mutual information -- the

interaction information and generalize it to multiparticle quantum systems.

There are a number of different possible generalizations. We consider two of

them. One of them is related to the notion of quantum discord and the other to

the concept of quantum dissension. This new measure, called dissension vector,

Quantum states, no matter pure states, density matrices or Wigner functions,

fully describe a physical system at a particular time. Time remains to be one

of the deepest mysteries in physics for centuries. Here we attempt to

understand time via a unified approach on both space and time, under the

intuition that relativity treats space and time on an equal footing; thus we

build quantum states across spacetime instead of only on spatial slices. We no

longer distinguish measurements on the same system at different times with

Quantum states for bipartite composite systems are categorised as either

separable or entangled, but the states can also be divided differently into

Bell local or Bell non-local states. This paper presents a detailed

classification of quantum states for bipartite systems and describes the

interrelationships between the various types. For the Bell local states there

are three cases depending on whether both, one of or neither of the local

hidden variable theory probabilities for each sub-system are also given by a

We propose a brand-new formulation of capacitated vehicle routing problem

(CVRP) as quadratic unconstrained binary optimization (QUBO). The formulated

CVRP is equipped with time-table which describes time-evolution of each

vehicle. Therefore, various constraints associated with time are successfully

realized. With a similar method, constraints of capacities are also introduced,

where capacitated quantities are allowed to increase and decrease according to

the cities which vehicles arrive. As a bonus of capacity-qubits, one also