Author(s): Iman Sargolzahi and Sayyed Yahya Mirafzali
We consider a bipartite quantum system $S=AB$ such that the part $A$ is isolated from the environment $E$ and only the part $B$ interacts with $E$. Under such circumstances, entanglement of the system may experience decreases and increases, during the evolution of the system. Here, we show that the ...
[Phys. Rev. A 97, 022331] Published Fri Feb 23, 2018

Author(s): Zhuo-Ping Hong, Bao-Jie Liu, Jia-Qi Cai, Xin-Ding Zhang, Yong Hu, Z. D. Wang, and Zheng-Yuan Xue
Geometric phases are well known to be noise resilient in quantum evolutions and operations. Holonomic quantum gates provide us with a robust way towards universal quantum computation, as these quantum gates are actually induced by non-Abelian geometric phases. Here we propose and elaborate how to ef...
[Phys. Rev. A 97, 022332] Published Fri Feb 23, 2018

Correlator product states (CPS) are a powerful and very broad class of states for quantum lattice
systems whose (unnormalised) amplitudes in a fixed basis can be sampled exactly and efficiently.
They work by gluing together states of overlapping clusters of sites on the lattice, called
correlators. Recently Carleo and Troyer (2017 Science 355 602) introduced a new type sampleable
ansatz called neural-network quantum states (NQS) that are inspired by the restricted Boltzmann

We consider a two dimensional extension of the so-called linearizable mappings. In particular, we
start from the Heideman–Hogan recurrence, which is known as one of the linearizable Somos-like
recurrences, and introduce one of its two dimensional extensions. The two dimensional lattice
equation we present is linearizable in both directions, and has the Laurent and the coprimeness
properties. Moreover, its reduction produces a generalized family of the Heideman–Hogan recurrence.

Devices relying on microwave circuitry form a cornerstone of many classical
and emerging quantum technologies. A capability to provide in-situ, noninvasive
and direct imaging of the microwave fields above such devices would be a
powerful tool for their function and failure analysis. In this work, we build
on recent achievements in magnetometry using ensembles of nitrogen vacancy
centres in diamond, to present a widefield microwave microscope with few-micron

Discrete quantum feedback control consists of a managed dynamics according to
the information acquired by a previous measurement. Energy fluctuations along
such dynamics satisfy generalized fluctuation relations, which are useful tools
to study the thermodynamics of systems far away from equilibrium. Due to the
practical challenge to assess energy fluctuations in the quantum scenario, the
experimental verification of detailed fluctuation relations in the presence of

We present a novel approach to the separability problem for Gaussian quantum
states of bosonic continuous variable systems. We derive a simplified necessary
and sufficient separability criterion for arbitrary Gaussian states of $m$ vs
$n$ modes, which relies on convex optimisation over marginal covariance
matrices on one subsystem only. We further revisit the currently known results
stating the equivalence between separability and positive partial transposition

The No Low-Energy Trivial States (NLTS) conjecture of Freedman and Hastings
(Quantum Information and Computation 2014), which asserts the existence of
local Hamiltonians whose low energy states cannot generated by constant depth
quantum circuits, identifies a fundamental obstacle to resolving the quantum
PCP conjecture. Progress towards the NLTS conjecture was made by Eldar and
Harrow (Foundations of Computer Science 2017), who proved a closely related
theorem called No Low-Error Trivial States (NLETS). In this paper, we give a

In an antiferromagnet (AF) with uniaxial anisotropy, spin-up and spin-down
magnon excitations coexist and form an internal degree of freedom. A magnon
spin current can be thermally generated near an exchange-coupled ferromagnet
(F)/AF interface where the degeneracy is lifted. Here we investigate thermal
magnon spin transport in an F/AF/F heterostructure. We find that a sufficiently
large temperature gradient can switch the downstream F via magnonic
spin-transfer torque if it is initially antiparallel with the upstream F.

We report on the sensing stability of quantum nanosensors in aqueous buffer
solutions for the two detection schemes of quantum decoherence spectroscopy and
nanoscale thermometry. The electron spin properties of single nitrogen-vacancy
(NV) centers in 25-nm-sized nanodiamonds have been characterized by tracking
individual nanodiamonds during a continuous change in pH from 4 to 11. We have
determined the stability of the NV quantum sensors during the pH change, which