Author(s): Da-Jiang Liu, Chi-Jen Wang, and James W. Evans
We consider Schloegl models (or contact processes) where particles on a square grid annihilate at a rate $p$ and are created at a rate of ${k}_{n}=n(n−1)/[N(N−1)]$ at empty sites with $n$ particles in a neighborhood ${\mathrm{Ω}}_{N}$ of size $N$. Simulation reveals a discontinuous transition betwee...
[Phys. Rev. Lett. 121, 120603] Published Fri Sep 21, 2018

Author(s): Feng Mei, Gang Chen, Lin Tian, Shi-Liang Zhu, and Suotang Jia
We propose a protocol using a tunable Xmon qubit chain to construct generalized Su-Schrieffer-Heeger (SSH) models that support various topological phases. We study the time evolution of a single-excitation quantum state in a SSH-type qubit chain and find that such dynamics is linked to the topologic...
[Phys. Rev. A 98, 032323] Published Fri Sep 21, 2018

Author(s): Chunhe Xiong, Asutosh Kumar, and Junde Wu
Coherence measures and their operational interpretations lay the cornerstone of coherence theory. In this paper, we introduce a class of coherence measures with $α$ affinity, say $α$ affinity of coherence for $α∈(0,1)$. Furthermore, we obtain the analytic formulas for these coherence measures and st...
[Phys. Rev. A 98, 032324] Published Fri Sep 21, 2018

We study theoretically how loss impacts the amplification and squeezing
performance of a generic quantum travelling wave parametric amplifier. Unlike
previous studies, we analyze how having different levels of loss at signal and
idler frequencies can dramatically alter properties compared to the case of
frequency-independent loss. We find that loss asymmetries increase the
amplifier's added noise in comparison to the symmetric loss case. More
surprisingly, even small levels of loss asymmetry can completely destroy any

The way in which energy is transported through an interacting system governs
fundamental properties in many areas of physics, chemistry, and biology.
Remarkably, environmental noise can enhance the transport, an effect known as
environment-assisted quantum transport (ENAQT). In this paper, we study ENAQT
in a network of coupled spins subject to engineered static disorder and
temporally varying dephasing noise. The interacting spin network is realized in
a chain of trapped atomic ions and energy transport is represented by the

The field of quantum algorithms aims to find ways to speed up the solution of
computational problems by using a quantum computer. A key milestone in this
field will be when a universal quantum computer performs a computational task
that is beyond the capability of any classical computer, an event known as
quantum supremacy. This would be easier to achieve experimentally than
full-scale quantum computing, but involves new theoretical challenges. Here we

It is demonstrated that detection of putative particles such as paraphotons
and axions constituting the dark sector of the universe can be reduced to
detection of extremely weak links or couplings between cavities and modes. This
method allows utilisation of extremely sensitive frequency metrology methods
that are not limited by traditional requirements on ultra low temperatures,
strong magnetic fields and sophisticated superconducting technology. We show

We investigate the transport properties and entanglement between spin and
position of one-dimensional quantum walks starting from a qubit over position
states following a delta-like (local state) and Gaussian (delocalized state)
distributions. We find out that if the initial state is delocalized enough and
a NOT gate reflects this state backwards, then the interference pattern
extinguishes the position dispersion without prevent the propagation of the

In this article, we investigate the numerical and theoretical aspects of the
coupled-cluster method tailored by matrix-product states. We investigate
chemical properties of the used method, such as energy size extensivity and the
equivalence of linked and unlinked formulation. The existing mathematical
analysis is here elaborated in a quantum chemical framework. In particular, we
highlight the use of a so-called CAS-ext gap describing the basis splitting

An assessment is given as to the extent to which pure unitary evolution, as
distinct from environmental decohering interaction, can provide the transition
necessary for an observer to interpret perceived quantum dynamics as classical.
This has implications for the interpretation of quantum wavefunctions as a
characteristic of ensembles or of single particles and the related question of
wavefunction collapse.