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In this paper, we study, both analytically and numerically, the localized modes in long Josephson
junctions in the presence of a variety of parametric drives. The phase-shift applied acts as a
double-well potential which is known as the ##IMG##
[http://ej.iop.org/images/1751-8121/52/1/015203/aaae951ieqn001.gif] junction. The system is
described by an inhomogeneous sine-Gordon equation that depicts the dynamics of long Josephson

The effect of a local instantaneous quantum dynamical process (QDP), either unitary or non-unitary,
on the quantum state transfer through a unitary Hamiltonian evolution is investigated for both
integrable and non-integrable dynamics. There are interference effects of the quantum state
propagation and the QDP signal propagation. The state transfer fidelity is small for further sites,
from the site where the information is coded, indicating a finite speed for the propagation of the

The paper presents a new method of geometric solution of a Schrödinger equation by constructing an
equivalent first-order partial differential equation with a bigger number of variables. The
equivalent equation shall be restricted to a specific subspace with auxiliary conditions which are
obtained from a coherent state transform. The method is applied to the fundamental case of the
harmonic oscillator and coherent state transform generated by the minimal nilpotent step three Lie

We obtain continuity bounds for basic information characteristics of quantum channels depending on
their input dimension (if it is finite) and on the input energy bound (if the input dimension is
infinite). We pay special attention to the case in which a multimode quantum oscillator is an input
system. First, we prove continuity bounds for the output conditional mutual information for a single

The thermodynamic uncertainty relation expresses a universal trade-off between precision and entropy
production, which applies in its original formulation to current observables in steady-state
systems. We generalize this relation to periodically time-dependent systems and, relatedly, to a
larger class of inherently time-dependent current observables. In the context of heat engines or
molecular machines, our generalization applies not only to the work performed by constant driving

The partial information decomposition (PID) is perhaps the leading proposal for resolving
information shared between a set of sources and a target into redundant, synergistic, and unique
constituents. Unfortunately, the PID framework has been hindered by a lack of a generally
agreed-upon, multivariate method of quantifying the constituents. Here, we take a step toward
rectifying this by developing a decomposition based on a new method that quantifies unique

Relative fluctuations of observables in discrete stochastic systems are bounded at all times by the
mean dynamical activity in the system, quantified by the mean number of jumps. This constitutes a
kinetic uncertainty relation that is fundamentally different from the thermodynamic uncertainty
relation recently discussed in the literature. The thermodynamic constraint is more relevant close
to equilibrium while the kinetic constraint is the limiting factor of the precision of a observables

Author(s): Luca Dellantonio, Anders S. Sørensen, and Davide Bacco
Quantum key distribution (QKD) provides ultimate cryptographic security based on the laws of quantum mechanics. For point-to-point QKD protocols, the security of the generated key is compromised by detector side channel attacks. This problem can be solved with measurement-device-independent QKD (mdi...
[Phys. Rev. A 98, 062301] Published Mon Dec 03, 2018

Author(s): Martin Šiler, Luca Ornigotti, Oto Brzobohatý, Petr Jákl, Artem Ryabov, Viktor Holubec, Pavel Zemánek, and Radim Filip
Stochastic motion of particles in a highly unstable potential generates a number of diverging trajectories leading to undefined statistical moments of the particle position. This makes experiments challenging and breaks down a standard statistical analysis of unstable mechanical processes and their ...
[Phys. Rev. Lett. 121, 230601] Published Mon Dec 03, 2018