# All

## Quantum localization bounds Trotter errors in digital quantum simulation. (arXiv:1806.11123v3 [quant-ph] UPDATED)

A fundamental challenge in digital quantum simulation (DQS) is the control of
inherent errors. These appear when discretizing the time evolution generated by
the Hamiltonian of a quantum many-body system as a sequence of quantum gates,
called Trotterization. Here, we show that quantum localization-by constraining
the time evolution through quantum interference-strongly bounds these errors
for local observables. Consequently, for generic quantum many-body

## Time-Reversal Symmetry and Arrow of Time in Quantum Mechanics of Open Systems. (arXiv:1903.05227v1 [quant-ph])

It is one of the most important and long-standing issues of physics to derive
the irreversibility out of a time-reversal symmetric equation of motion. The
present paper considers the breaking of the time-reversal symmetry in open
quantum systems and the emergence of an arrow of time. We claim that the
time-reversal symmetric Schr\"{o}dinger equation can have eigenstates that
break the time-reversal symmetry if the system is open in the sense that it has
at least a countably infinite number of states. Such eigenstates, namely the

## Opportunities for Nuclear Physics & Quantum Information Science. (arXiv:1903.05453v1 [nucl-th])

This whitepaper is an outcome of the workshop Intersections between Nuclear
Physics and Quantum Information held at Argonne National Laboratory on 28-30
March 2018 [www.phy.anl.gov/npqi2018/]. The workshop brought together 116
national and international experts in nuclear physics and quantum information
science to explore opportunities for the two fields to collaborate on topics of
interest to the U.S. Department of Energy (DOE) Office of Science, Office of

## Adversarial vs cooperative quantum estimation. (arXiv:1808.03854v2 [quant-ph] UPDATED)

We address the estimation of a one-parameter family of isometries taking one
input into two output systems. This primarily allows us to consider imperfect
estimation by accessing only one output system, i.e. through a quantum channel.
Then, on the one hand, we consider separate and adversarial control of the two
output systems to introduce the concept of \emph{privacy of estimation}. On the
other hand we conceive the possibility of separate but cooperative control of

## Conditional past-future correlation induced by non-Markovian dephasing reservoirs. (arXiv:1903.05259v1 [quant-ph])

Memory effects can be studied through a conditional past-future correlation,
which measures departure with respect to a conditional past-future independence
valid in a memoryless Markovian regime. In a quantum regime this property leads
to an operational definition of quantum non-Markovianity based on three
consecutive system measurement processes and postselection [Budini, Phys. Rev.
Lett. 121, 240401 (2018)]. Here, we study the conditional past-future
correlation for a qubit system coupled to different dephasing environments.

## Quantum simulation of the spinor-4 Dirac equation with an artificial gauge field. (arXiv:1903.05482v1 [cond-mat.quant-gas])

A two-dimensional spatially and temporally modulated Wannier-Stark system of
ultracold atoms in optical lattices is shown to mimic the behavior of a Dirac
particle. Suitable additional modulations generate an artificial gauge field
which simulates a magnetic field and imposes the use of the full spinor-4 Dirac
equation.

## Quadratic Quantum Hamiltonians: General Canonical Transformation to a Normal Form. (arXiv:1809.09499v2 [quant-ph] UPDATED)

A system of linearly coupled quantum harmonic oscillators can be diagonalized
when the system is dynamically stable using a Bogoliubov canonical
transformation. However, this is just a particular case of more general
canonical transformations that can be performed even when the system is
dynamically unstable. Specific canonical transformations can transform a
quadratic Hamiltonian into a normal form, which greatly helps to elucidate the
underlying physics of the system. Here, we provide a self-contained review of

## Electron Counting Statistics for Non-Additive Environments. (arXiv:1903.05264v1 [cond-mat.mes-hall])

Molecular electronics is a rapidly developing field focused on using
molecules as the structural basis for electronic components. It is common in
such devices for the system of interest to couple simultaneously to multiple
environments. Here we consider a model comprised of a double quantum dot (or
molecule) coupled strongly to vibrations and weakly to two electronic leads
held at arbitrary bias voltage. The strong vibrational coupling invalidates
treating the bosonic and electronic environments simply as acting additively,

## Quantum Critical Dynamics of a Heisenberg-Ising Chain in a Longitudinal Field: Many-Body Strings versus Fractional Excitations. (arXiv:1903.05492v1 [cond-mat.str-el])

We report a high-resolution terahertz spectroscopic study of quantum spin
dynamics in the antiferromagnetic Heisenberg-Ising spin-chain compound
BaCo$_2$V$_2$O$_8$ as a function of temperature and longitudinal magnetic
field. Confined spinon excitations are observed in an antiferromagnetic phase
below $T_N\simeq 5.5$ K. In a field-induced gapless phase above $B_c=3.8$ T, we
identify many-body string excitations as well as low-energy fractional
psinon/antipsinon excitations by comparing to Bethe-Ansatz calculations. In the

## Effective Hamiltonian theory of the geometric evolution of quantum systems. (arXiv:1810.00193v2 [quant-ph] UPDATED)

In this work we present an effective Hamiltonian description of the quantum
dynamics of a generalized Lambda system undergoing adiabatic evolution. We
assume the system to be initialized in the dark subspace and show that its
holonomic evolution can be viewed as a conventional Hamiltonian dynamics in an
appropriately chosen extended Hilbert space. In contrast to the existing
approaches, our method does not require the calculation of the non-Abelian
Berry connection and can be applied without any parametrization of the dark