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We propose and analyze a scanning microscope to monitor `live' the quantum
dynamics of cold atoms in a Cavity QED setup. The microscope measures the
atomic density with subwavelength resolution via dispersive couplings to a
cavity and homodyne detection within the framework of continuous measurement
theory. We analyze two modes of operation. First, for a fixed focal point the
microscope records the wave packet dynamics of atoms with time resolution set
by the cavity lifetime. Second, a spatial scan of the microscope acts to map

We consider superconducting circuits for the purpose of simulating the
spin-boson model. The spin-boson model consists of a single two-level system
coupled to bosonic modes. In most cases, the model is considered in a limit
where the bosonic modes are sufficiently dense to form a continuous spectral
bath. A very well known case is the ohmic bath, where the density of states
grows linearly with the frequency. In the limit of weak coupling or large
temperature, this problem can be solved numerically. If the coupling is strong,

The quantum assembly language (QASM) is a popular intermediate representation
used in many quantum compilation and simulation tools to describe quantum
circuits. Currently, multiple different dialects of QASM are used in different
quantum computing tools. This makes the interaction between those tools tedious
and time-consuming due to the need for translators between theses different
syntaxes. Beside requiring a multitude of translators, the translation process

Quantum measurements based on mutually unbiased bases are commonly used in
quantum information processing, as they are generally viewed as being maximally
incompatible and complementary. Here we quantify precisely the degree of
incompatibility of mutually unbiased bases (MUB) using the notion of noise
robustness. Specifically, for sets of $k$ MUB in dimension $d$, we provide
upper and lower bounds on this quantity. Notably, we get a tight bound in
several cases, in particular for complete sets of $k=d+1$ MUB (given $d$ is a

We develop a scheme of fast forward of adiabatic spin dynamics of quantum
entangled states. We settle the quasi-adiabatic dynamics by adding the
regularization terms to the original Hamiltonian and then accelerate it with
use of a large time-scaling factor. Assuming the experimentally-realizable
candidate Hamiltonian consisting of the exchange interactions and magnetic
field, we solved the regularization terms. These terms multiplied by the
velocity function give rise to the state-dependent counter-diabatic terms. The

The investigation of macroscopic quantum phenomena is a current active area
of research that offers significant promise to advance the forefronts of both
fundamental and applied quantum science. Utilizing the exquisite precision and
control of quantum optics provides a powerful toolset for generating such
quantum states where the types and 'size' of the states that can be generated
are set by the resourcefulness of the protocol applied. In this work we present

We study the dynamics of a quantum system whose interaction with an
environment is described by a non-Markovian collision model. We identify the
relevant system-environment correlations that lead to a non-Markovian
evolution. Through an equivalent picture of the open dynamics, we introduce the
notion of "memory depth" where these correlations are established between the
system and a suitably sized memory rendering the overall system+memory
evolution Markovian. We extend our analysis to show that while most

Given a parameterized quantum circuit such that a certain setting of these
real-valued parameters corresponds to Grover's celebrated search algorithm, can
a variational algorithm recover these settings and hence learn Grover's
algorithm? We tried several constrained variations of this problem and answered
this question in the affirmative, with some caveats. Grover's quantum search
algorithm is optimal up to a constant. The success probability of Grover's

A non-Hermitian extension of the Chern insulator and its bulk-boundary
correspondence are investigated. It is shown that in addition to the robust
chiral edge states that reflect the nontrivial topology of the bulk (nonzero
Chern number), the anomalous helical edge states localized only at one edge can
appear, which are unique to the non-Hermitian Chern insulator.

A weak measurement performed on a pre- and post-selected quantum system can
result in an average value that lies outside of the observable's spectrum. This
effect, usually referred to as an "anomalous weak value", is generally believed
to be possible only when a non-trivial post-selection is performed, i.e., when
only a particular subset of the data is considered. Here we show, however, that
this is not the case in general: in scenarios in which several weak
measurements are sequentially performed, an anomalous weak value can be