We apply advanced methods of control theory to open quantum systems and we
determine finite-time processes which are optimal with respect to thermodynamic
performances. General properties and necessary conditions characterizing
optimal drivings are derived, obtaining bang-bang type solutions corresponding
to control strategies switching between adiabatic and isothermal
transformations. A direct application of these results is the maximization of
the work produced by a generic quantum heat engine, where we show that the

In this study, we solve analytically the Schrodinger equation for a
macroscopic quantum oscillator as a central system coupled to a large number of
environmental micro-oscillating particles. Then, the Langevin equation is
obtained for the system using two approaches: Quantum Mechanics and Bohmian
Theory. Our results show that the predictions of the two theories are
inherently different in real conditions. Nevertheless, the Langevin equation
obtained by Bohmian approach could be reduced to the quantum one, when the

PT-symmetric quantum mechanics allows finding stationary states in mean-field
systems with balanced gain and loss of particles. In this work we apply this
method to rotating Bose-Einstein condensates with contact interaction which are
known to support ground states with vortices. Due to the particle exchange with
the environment transport phenomena through ultracold gases with vortices can
be studied. We find that even strongly interacting rotating systems support

Entanglement distribution is a prerequisite for several important quantum
information processing and computing tasks, such as quantum teleportation,
quantum key distribution, and distributed quantum computing. In this work, we
focus on two-dimensional quantum networks based on optical quantum technologies
using dual-rail photonic qubits. We lay out a quantum network architecture for
entanglement distribution between distant parties, with the technological
constraint that quantum repeaters equipped with quantum memories are not

We investigate the use of twin-mode quantum states of light with symmetric
statistical features in their photon number for improving intensity-sensitive
surface plasmon resonance (SPR) sensors. For this purpose, one of the modes is
sent into a prism setup where the Kretschmann configuration is employed as a
sensing platform and the analyte to be measured influences the SPR excitation
conditions. This influence modifies the output state of light that is
subsequently analyzed by an intensity-difference measurement scheme. We show

We report on the existence and stability of freely moving solitons in a
spatially inhomogeneous Bose- Einstein condensate with helicoidal spin-orbit
(SO) coupling. In spite of the periodically varying parameters, the system
allows for the existence of stable propagating solitons. Such states are found
in the rotating frame, where the helicoidal SO coupling is reduced to a
homogeneous one. In the absence of the Zeeman splitting, the coupled
Gross-Pitaevskii equations describing localized states feature many properties

Dynamical decoupling as one of quantum control strategies aimed at
suppressing quantum decoherence adopt the popular philosophy that the disorder
in the unitary evolution of the open quantum system caused by environmental
noises should be neutralized by a sequence of ordered or well-designed external
operations acting on the system. This work studies the exact solution of
quantum-state-diffusion equations by mixing two channels of environmental
noises, i.e., relaxation (dissipation) and dephasing. It is interesting to find

The quantum autoencoder is a recent paradigm in the field of quantum machine
learning, which may enable an enhanced use of resources in quantum
technologies. To this end, quantum neural networks with less nodes in the inner
than in the outer layers were considered. Here, we propose a useful connection
between approximate quantum adders and quantum autoencoders. Specifically, this
link allows us to employ optimized approximate quantum adders, obtained with
genetic algorithms, for the implementation of quantum autoencoders for a

Given an arbitrary quantum state ($\sigma$), we obtain an explicit
construction of a state $\rho^*_\varepsilon(\sigma)$ (resp.
$\rho_{*,\varepsilon}(\sigma)$) which has the maximum (resp. minimum) entropy
among all states which lie in a specified neighbourhood ($\varepsilon$-ball) of
$\sigma$. Computing the entropy of these states leads to a local strengthening
of the continuity bound of the von Neumann entropy, i.e., the Audenaert-Fannes
inequality. Our bound is local in the sense that it depends on the spectrum of

We show that Gibbs states of non-homogeneous transverse Ising chains satisfy
a \emph{shielding} property. Namely, whatever the fields on each spin and
exchange couplings between neighboring spins are, if the field in one
particular site is null, the reduced states of the subchains to the right and
to the left of this site are \emph{exactly} the Gibbs states of each subchain
alone. Therefore, even if there is a strong exchange coupling between the
extremal sites of each subchain, the Gibbs states of the each subchain behave