Experimental implementation of a quantum computing algorithm strongly relies
on the ability to construct required unitary transformations applied to the
input quantum states. In particular, near-term linear optical computing
requires universal programmable interferometers, capable of implementing an
arbitrary transformation of input optical modes. So far these devices were
composed as a circuit with well defined building blocks, such as balanced
beamsplitters. This approach is vulnerable to manufacturing imperfections

Weyl points, synthetic magnetic monopoles in the 3D momentum space, are the
key features of topological Weyl semimetals. The observation of Weyl points in
ultracold atomic gases usually relies on the realization of high-dimensional
spin-orbit coupling (SOC) for two pseudospin states (% \textit{i.e.,}
spin-1/2), which requires complex laser configurations and precise control of
laser parameters, thus has not been realized in experiment. Here we propose
that robust Wely points can be realized using 1D triple-well superlattices

The vast and growing number of publications in all disciplines of science
cannot be comprehended by a single human researcher. As a consequence,
researchers have to specialize in narrow sub-disciplines, which makes it
challenging to uncover scientific connections beyond the own field of research.
Thus access to structured knowledge from a large corpus of publications could
help pushing the frontiers of science. Here we demonstrate a method to build a
semantic network from published scientific literature, which we call SemNet. We

Two time-reversal quantum key distribution (QKD) schemes are the quantum
entanglement based device-independent (DI)-QKD and
measurement-device-independent (MDI)-QKD. The recently proposed twin field
(TF)-QKD, also known as phase-matching (PM)-QKD, has improved the key rate
bound from $O\left( \eta \right )$ to $O\left( \sqrt {\eta} \right )$ with
$\eta$ the channel transmittance. In fact, TF-QKD is a kind of MDI-QKD but
based on single-photon detection. In this paper, we propose a different PM-QKD

We analyse the charging process of quantum batteries with general harmonic
power. To describe the charge efficiency, we introduce the charge saturation
and the charging power, and divide the charging mode into the saturated
charging mode and the unsaturated charging mode. The relationships between the
time-dependent charge saturation and the parameters of general driving field
are discussed both analytically and numerically. And according to the Floquet

The Carnot cycle combines reversible isothermal and adiabatic strokes to
obtain optimal efficiency, at the expense of a vanishing power output. Here, we
construct quantum Carnot-analog cycles, operating irreversibly at non-vanishing
power. Swift thermalization is obtained utilizing shortcut to equilibrium
protocols and the isolated strokes employ frictionless shortcut to adiabaticity
protocols. We solve the dynamics for a working medium composed of a particle in

We consider a fractional generalization of two-dimensional (2D)
quantum-mechanical Kepler problem corresponding to 2D hydrogen atom. Our main
finding is that the solution for discreet spectrum exists only for $\mu>1$
(more specifically $1 < \mu \leq 2$, where $\mu=2$ corresponds to "ordinary" 2D
hydrogenic problem), where $\mu$ is the L\'evy index. We show also that in
fractional 2D hydrogen atom, the orbital momentum degeneracy is lifted so that
its energy starts to depend not only on principal quantum number $n$ but also

We introduce a model to study the collisions of two ultracold diatomic
molecules in one dimension interacting via pairwise potentials. We present
results for this system, and argue that it offers lessons for real molecular
collisions in three dimensions. We analyze the distribution of the adiabatic
potentials in the hyperspherical coordinate representation as well as the
distribution of the four-body bound states in the adiabatic approximation (i.e.
no coupling between adiabatic channels). It is found that while the adiabatic

We analyse quasi-periodically driven quantum systems that can be mapped
exactly to periodically driven ones and find Floquet Time Spirals in analogy
with spatially incommensurate spiral magnetic states. Generalising the
mechanism to many-body systems we discover that a form of discrete
time-translation symmetry breaking can also occur in quasi-periodically driven
systems. We construct a discrete time quasi-crystal stabilised by many-body
localisation, which persists also under perturbations that break the

We present a detailed study of the topological Schwinger model
[$\href{this http URL}{Phys. \; Rev.\; D \; {\bf
99},\;014503 \; (2019)}$], which describes (1+1) quantum electrodynamics of an
Abelian $U(1)$ gauge field coupled to a symmetry-protected topological matter
sector, by means of a class of $\mathbb{Z}_N$ lattice gauge theories. Employing
density-matrix renormalization group techniques that exactly implement Gauss'