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Entanglement entropy in topologically ordered matter phases has been computed
extensively using various methods. In this paper, we study the entanglement
entropy of topological phases in two-spaces from a new perspective---the
perspective of quasiparticle fluctuations. In this picture, the entanglement
spectrum of a topologically ordered system is identified with the spectrum of
quasiparticle fluctuations of the system, and the entanglement entropy measures
the maximal quasiparticle fluctuations on the EB. As a consequence,

Current approaches to quantum gravity suggest there should be a modification
of the standard quantum mechanical commutator, $[{\hat x} , {\hat p}] = i
\hbar$. Typical modifications are phenomenological and designed to result in a
minimal length scale. As a motivating principle for the modification of the
position and momentum commutator, we assume the validity of a version of the
Bender-Brody-M\"uller variant of the Berry-Keating approach to the Riemann

Modern neuroscience is currently limited in its capacity to perform long
term, wide-field measurements of neuron electromagnetics with nanoscale
resolution. Quantum microscopy using the nitrogen vacancy centre (NV) can
provide a potential solution to this problem with electric and magnetic field
sensing at nano-scale resolution and good biocompatibility. However, the
performance of existing NV sensing technology does not allow for studies of
small mammalian neurons yet. In this paper, we propose a solution to this

In a couple of recent preprints Moldoveanu has suggested that there are
errors in my disproof of Bell's theorem. Here I show that this claim is false.
In particular, I show that my local-realistic framework is incorrectly and
misleadingly presented in both of his preprints. In addition there are a number
of serious mathematical and conceptual errors in his discussion of my
framework. For example, contrary to his claim, my framework is manifestly
non-contextual. In particular, quantum correlations are understood within it as

The efficient creation and detection of spatial modes of light has become
topical of late, driven by the need to increase photon-bit-rates in classical
and quantum communications. Such mode creation/detection is traditionally
achieved with tools based on linear optics. Here we put forward a new spatial
mode detection technique based on the nonlinear optical process of
sum-frequency generation. We outline the concept theoretically and demonstrate
it experimentally with intense laser beams carrying orbital angular momentum

We implement the reinforcement learning agent for a spin-1 atomic system to
prepare spin squeezed state from given initial state. Proximal policy gradient
(PPO) algorithm is used to deal with continuous external control field and
final optimized protocol is given by a stochastic policy. In both mean-field
system and two-body quantum system, RL agent finds the optimal policies. In
many-body quantum system, it also gives polices that outperform purely greedy

Studying the time development of the expectation value in the
future-not-included complex action theory, we point out that the momentum
relation (the relation analogous to $p=\frac{\partial L}{\partial \dot{q}}$),
which was derived via the Feynman path integral and was shown to be correct in
the future-included theory in our previous papers, is not valid in the
future-not-included theory. We provide the correct momentum relation in the
future-not-included theory, and argue that the future-not-included classical

The Wigner function's behavior of accelerated and non-accelerated Greenberger
Horne Zeilinger (GHZ) state is discussed. For the non-accelerated GHZ state,
the minimum/maximum peaks of the Wigner function depends on the distribution's
angles, where they are displayed regularly at fixed values of the
distribution's angles. We show that, for the accelerated GHZ state, the minimum
bounds increases as the acceleration increases. The increasing rate depends on

We present an alternative method for determining the sound velocity in atomic
Bose-Einstein condensates, based on thermodynamic global variables. The total
number of trapped atoms was as a function of temperature carefully studied
across the phase transition, at constant volume. It allowed us to evaluate the
sound velocity resulting in consistent values from the quantum to classical
regime, in good agreement with previous results found in literature. We also

Witness operators are a central tool to detect entanglement or to distinguish
among the different entanglement classes of multiparticle systems, which can be
defined using stochastic local operations and classical communication (SLOCC).
We show a one-to-one correspondence between general SLOCC witnesses and a class
of entanglement witnesses in an extended Hilbert space. This relation can be
used to derive SLOCC witnesses from criteria for full separability of quantum