In quantum information, lifting is a procedure employed to derive a Bell

inequality applicable in a more complicated Bell scenario from an existing one.

It is known that the procedure of lifting considered by Pironio [J. Math. Phys.

A 46, 062112 (2005)] preserves the facet-defining property of a Bell

inequality. Here, we perform a complementary investigation showing that the

maximal value of a lifted Bell inequality is preserved for both the set of

non-signaling correlations and quantum correlations. Moreover, the optimal

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Evidence for Bell's nonlocality is so far mainly restricted to microscopic

systems, where the elements of reality that are negated predetermine results of

measurements to within one spin unit. Any observed nonlocal effect (or lack of

classical predetermination) is then limited to no more than the difference of a

single photon or electron being detected or not (at a given detector). In this

paper, we analyze experiments that report Einstein-Podolsky-Rosen (EPR)

steering form of nonlocality for mesoscopic photonic or Bose-Einstein

Entangling operations are among the most important primitive gates employed

in quantum computing and it is crucial to ensure high-fidelity implementations

as systems are scaled up. We experimentally realize and characterize a simple

scheme to minimize errors in entangling operations related to the residual

excitation of mediating bosonic oscillator modes that both improves

gate-robustness and provides scaling benefits in larger systems. The technique

employs discrete phase shifts in the control field driving the gate operation,

We investigate how topological entanglement of Chern-Simons theory is

captured in a string theoretic realization. Our explorations are motivated by a

desire to understand how quantum entanglement of low energy open string degrees

of freedom is encoded in string theory (beyond the oft discussed classical

gravity limit). Concretely, we realize the Chern-Simons theory as the

worldvolume dynamics of topological D-branes in the topological A-model string

theory on a Calabi-Yau target. Via the open/closed topological string duality

The monopole for the geometric curvature is studied for non-Hermitian

systems. We find that the monopole contains not only the exceptional points but

also branch cuts. As the mathematical choice of branch cut in the complex plane

is rather arbitrary, the monopole changes with the branch-cut choice. Despite

this branch-cut dependence, our monopole is invariant under the

$GL(l,\mathbb{C})$ gauge transformation that is inherent in non-Hermitian

systems. Although our results are generic, they are presented in the context of

State preparation protocols ideally require as minimal operations as

possible, in order to be implemented in near-term, potentially noisy quantum

devices. Motivated by long range interactions (LRIs) intrinsic to many

present-day experimental platforms (trapped ions, Rydberg atom arrays, etc.),

we investigate the efficacy of variationally simulating non-trivial quantum

states using the Variational Quantum-Classical Simulation (VQCS) protocol

explored recently in [SciPost Phys. 6, 029 (2019)], in the presence of LRIs. We

In this article we provide a method for fully quantum generative training of

quantum Boltzmann machines with both visible and hidden units while using

quantum relative entropy as an objective. This is significant because prior

methods were not able to do so due to mathematical challenges posed by the

gradient evaluation. We present two novel methods for solving this problem. The

first proposal addresses it, for a class of restricted quantum Boltzmann

machines with mutually commuting Hamiltonians on the hidden units, by using a

Quantum fluctuations associated with the ground state of a system exist as a

consequence of Heisenberg's uncertainty principle. These fluctuating fields

manifest themselves indirectly through their influence on matter which has been

extensively studied by considering e.g. the Casimir and Casimir-Polder force.

More recently, these ground state fluctuations have been measured directly

using nonlinear crystals by means of electro-optical sampling. Despite their

common origin, these direct versus indirect evidence of ground-state

Using criteria based on superselection rules, we analyze the quantum

correlations between the two condensate modes of the Bose-Einstein condensate

interferometer of Egorov et al. [Phys. Rev. A 84, 021605 (2011)]. In order to

determine the two-mode correlations, we develop a multi-mode theory that

describes the dynamics of the condensate atoms and the thermal fraction through

the interferometer sequence, in agreement with the experimentally measured

fringe visibility. We thus present experimental evidence for two-mode entangled

A comprehensive study of three-photon electromagnetically-induced

transparency (EIT) and absorption (EIA) on the rubidium cascade $5S_{1/2}

\rightarrow 5P_{3/2}$ (laser wavelength 780~nm), $5P_{3/2} \rightarrow

5D_{5/2}$ (776~nm), and $5D_{5/2}\rightarrow 28F_{7/2}$ (1260~nm) is performed.

The 780-nm probe and 776-nm dressing beams are counter-aligned through a Rb

room-temperature vapor cell, and the 1260-nm coupler beam is co- or

counter-aligned with the probe beam. Several cases of EIT and EIA, measured