Quantum repeaters -- important components of a scalable quantum internet --
enable the entanglement to be distributed over long distances. The standard
paradigm for a quantum repeater relies on a necessary demanding requirement of
quantum memory. Despite significant progress, the limited performance of
quantum memory makes practical quantum repeaters still a great challenge.
Remarkably, a proposed all-photonic quantum repeater avoids the need for
quantum memory by harnessing the graph states in the repeater nodes. Here we

A full-dimensional \emph{ab initio} potential energy surface of spectroscopic
quality is developed for the van-der-Waals complex of a methane molecule and an
argon atom. Variational vibrational states are computed on this surface
including all twelve (12) vibrational degrees of freedom of the methane-argon
complex using the GENIUSH computer program and the Smolyak sparse grid method.
The full-dimensional computations make it possible to study fine details of the

In this paper, we mainly study the local distinguishable multipartite quantum
states by local operations and classical communication (LOCC) in $m_1\otimes
m_2\otimes\ldots\otimes m_n$ , where the quantum system $m_1$ belongs to Alice,
$m_2$ belongs to Bob, \ldots and $m_n$ belongs to Susan. We first present the
pure tripartite distinguishable orthogonal quantum states by LOCC in
$m_1\otimes m_2\otimes m_3$. With the conclusion in $m_1\otimes m_2\otimes
m_3$, we prove distinguishability or indistinguishability of some quantum

Cavity-magnon polaritons (CMPs) are the associated quasiparticles of a
hybridization between cavity photons and magnons in a magnetic sample placed in
a microwave resonator. In the strong coupling regime, where the macroscopic
coupling strength exceeds the individual dissipation, there is a coherent
exchange of information. This renders CMPs as promising candidates for future
applications such as in information processing. Recent progress on the study of
the CMP allows now not only to obtain CMPs, but also to tune the coupling

Optical lattice systems provide exceptional platforms for quantum simulation
of many-body systems. We focus on the doubly modulated Bose-Hubbard model
driven by both time-dependent on-site energy and interaction, and predict the
emergence of the nearest neighbour interaction and density-assisted tunnelling.
By specifically designing a bi-chromatic driving pattern for a one dimensional
lattice, we demonstrate that the doubly modulated fields can be tuned to

We address the quantum estimation of parameters encoded into the initial
state of two modes of a Dirac field described by relatively accelerated
parties. By using the quantum Fisher information (QFI), we investigate how the
weak measurements performed before and after the accelerating observer, affect
the optimal estimation of information encoded into the weight and phase
parameters of the initial state shared between the parties. Studying the QFI,
associated with weight parameter $ \vartheta $, we find that the acceleration

We develop a generic model for a cyclic quantum heat engine that makes it
possible to coherently amplify a periodically modulated input signal without
the need to couple the working medium to multiple reservoirs at the same time.
Instead, we suggest an operation principle that is based on the spontaneous
creation of population inversion in incomplete relaxation processes induced by
periodic temperature variations. Focusing on Lindblad dynamics and systems with

The framework of Wigner functions for the canonical pair angle and orbital
angular momentum, derived and analyzed in 2 recent papers [H. A. Kastrup,
Phys.Rev. A 94, 062113(2016) and Phys.Rev. A 95, 052111(2017)] is applied to
elementary concepts of quantum information like qubits and 2-qubits, e.g.,
entangled EPR/Bell states etc. Properties of the associated Wigner functions of
such superposed states (pure and mixed) are discussed and illustrated. The
Wigner functions of ERP/Bell states are distinguished by their topologically

We review recent advances in the research on quantum parametric phenomena in
superconducting circuits with Josephson junctions. We discuss physical
processes in parametrically driven tunable cavity and outline theoretical
foundations for their description. Amplification and frequency conversion are
discussed in detail for degenerate and non-degenerate parametric resonance,
including quantum noise squeezing and photon entanglement. Experimental
advances in this area played decisive role in successful development of quantum

The study of quantum resonances in the chaotic atom-optics kicked rotor
system is of interest from two different perspectives. In quantum chaos, it
marks out the regime of resonant quantum dynamics in which the atomic cloud
displays ballistic mean energy growth due to coherent momentum transfer.
Secondly, the sharp quantum resonance peaks are useful in the context of
measurement of Talbot time, one of the parameter that helps in precise
measurement of fine structure constant. Most of the earlier works rely on