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The Darmois-Skitovich theorem is a simple characterization of the normal
distribution in terms of the independence of linear forms. We present here a
non-commutative version of this theorem in the context of Gaussian bosonic
states and show that this theorem is stable under small errors in its
underlying conditions. An explicit estimate of the stability constants which
depend on the physical parameters of the problem is given.

We propose a reliable scheme to realize the ultrastrong Jaynes-Cummings (JC)
model by simultaneously modulating the resonance frequencies of the two-level
system and the bosonic mode in the ultrastrong quantum Rabi model. We find that
in both the high- and low-frequency modulation regimes, the counter-rotating
terms can be completely suppressed without reducing the coupling strength of
the rotating-wave terms, and hence the ultrastrong JC Hamiltonian is achieved.

We investigate unambiguous discrimination between given quantum states with a
sequential measurement, which is restricted to local measurements and one-way
classical communication. If the given states are binary or those each of whose
individual systems is two-dimensional, then it is in some cases known whether a
sequential measurement achieves a globally optimal unambiguous measurement. In
contrast, for more than two states each of whose individual systems is more

We investigate the mean-field phase diagram of the Bose-Hubbard model with
infinite-range interactions in two dimensions. This model describes ultracold
bosonic atoms confined by a two-dimensional optical lattice and dispersively
coupled to a cavity mode with the same wavelength as the lattice. We determine
the ground-state phase diagram for a grand-canonical ensemble by means of
analytical and numerical methods. Our results mostly agree with the ones
reported in Dogra et al. [PRA 94, 023632 (2016)], and have a remarkable

Recent studies using the quantum information theoretic approach to
thermodynamics show that the presence of coherence in quantum systems generates
corrections to classical fluctuation theorems. To explicate the physical
origins and implications of such corrections, we here convert an abstract
framework of an autonomous quantum Crooks relation into quantum Crooks
equalities for well-known coherent, squeezed and cat states. We further provide
a proposal for a concrete experimental scenario to test these equalities. Our

The braiding of two non-Abelian Majorana modes is important for realizing
topological quantum computation. It can be achieved through tuning the coupling
between the two Majorana modes to be exchanged and two ancillary Majorana
modes. However, this coupling also makes the braiding subject to
environment-induced decoherence. Here, we study the effects of decoherence on
the diabatic errors in the braiding process for a set of time-dependent
Hamiltonians with finite smoothness. To this end, we employ the master equation

The development of microwave photon detectors is paving the way for a wide
range of quantum technologies and fundamental discoveries involving single
photons. Here, we investigate the photon emission from a microwave cavity and
find that distribution of photon waiting times contains information about
few-photon processes, which cannot easily be extracted from standard
correlation measurements. The factorial cumulants of the photon counting
statistics are positive at all times, which may be intimately linked with the

We consider a spin $s$ subjected to both a static and an orthogonally applied
oscillating, circularly polarized magnetic field while being coupled to a heat
bath, and analytically determine the quasi\-stationary distribution of its
Floquet-state occupation probabilities for arbitrarily strong driving. This
distribution is shown to be Boltzmannian with a quasitemperature which is
different from the temperature of the bath, and independent of the spin quantum
number. We discover a remarkable formal analogy between the quasithermal

Mechanical systems facilitate the development of a new generation of hybrid
quantum technology comprising electrical, optical, atomic and acoustic degrees
of freedom. Entanglement is the essential resource that defines this new
paradigm of quantum enabled devices. Continuous variable (CV) entangled fields,
known as Einstein-Podolsky-Rosen (EPR) states, are spatially separated two-mode
squeezed states that can be used to implement quantum teleportation and quantum

The field of optomechanics provides us with several examples of quantum
photon-phonon interface. In this paper, we theoretically investigate the
generation and manipulation of quantum correlations in a microfabricated
optomechanical array. We consider a system consisting of localized photonic and
phononic modes interacting locally via radiation pressure at each lattice site
with the possibility of hopping of photons and phonons between neighboring
sites. We show that such an interaction can correlate various modes of a driven