# All

## Gravitational mass of composite systems. (arXiv:1808.05831v2 [gr-qc] UPDATED)

The equivalence principle in combination with the special relativistic
equivalence between mass and energy, $E=mc^2$, is one of the cornerstones of
general relativity. However, for composite systems a long-standing result in
general relativity asserts that the passive gravitational mass is not simply
equal to the total energy. This seeming anomaly is supported by all explicit
derivations of the dynamics of bound systems, and is only avoided after
time-averaging. Here we rectify this misconception and derive from first

## Observation of PT-symmetric quantum interference. (arXiv:1904.08135v1 [quant-ph])

Parity-Time (PT) symmetric quantum mechanics is a complex extension of
conventional Hermitian quantum mechanics in which physical observables possess
a real eigenvalue spectrum. However, an experimental demonstration of the true
quantum nature of PT symmetry has been elusive thus far, as only
single-particle physics has been exploited to date. In our work, we demonstrate
two-particle quantum interference in a PT-symmetric system. We employ
integrated photonic waveguides to reveal that PT-symmetric bunching of

## Unifying fast scrambling, thermalization and entanglement through the measurement of FOTOCs in the Dicke model. (arXiv:1808.07134v3 [quant-ph] UPDATED)

Scrambling of quantum information is the process by which information
initially stored in the local degrees of freedom of a quantum many-body system
spreads over its many-body degrees of freedom, becoming inaccessible to local
probes and thus apparently lost. Scrambling and entanglement are key concepts
reconciling seemingly unrelated behaviors including thermalization of isolated
quantum systems and information loss in black holes, and have revolutionized

## Engineering spin squeezing in a 3D optical lattice with interacting spin-orbit-coupled fermions. (arXiv:1904.07866v1 [quant-ph])

One of the most important tasks in modern quantum science is to coherently
control and entangle many-body systems, and to subsequently use these systems
to realize powerful quantum technologies such as quantum-enhanced sensors.
However, many-body entangled states are difficult to prepare and preserve since
internal dynamics and external noise rapidly degrade any useful entanglement.
Here, we introduce a protocol that counterintuitively exploits inhomogeneities,

## Generation of optical Fock and W states with single-atom-based bright quantum scissors. (arXiv:1904.08197v1 [quant-ph])

We introduce a multi-step protocol for optical quantum state engineering that
performs as deterministic "bright quantum scissors" (BQS), namely truncates an
arbitrary input quantum state to have at least a certain number of photons. The
protocol exploits single-photon pulses and is based on the effect of
single-photon Raman interaction, which is implemented with a single three-level
$\Lambda$ system (e.g. a single atom) Purcell-enhanced by a single-sided
cavity. A single step of the protocol realises the inverse of the bosonic

## Many-body quantum metrology with scalar bosons in a single potential well. (arXiv:1809.08093v3 [quant-ph] UPDATED)

We theoretically investigate the possibility of performing high precision
estimation of an externally imposed acceleration using scalar bosons in a
single-well trap. We work at the level of a two-mode truncation, valid for weak
to intermediate two-body interaction couplings.The splitting process into two
modes is in our model entirely caused by the interaction between the
constituent bosons and is hence neither due to an externally imposed
double-well potential nor due to populating a spinor degree of freedom. The

## The Collapse Before a Quantum Jump Transition. (arXiv:1904.07890v1 [quant-ph])

We may infer a transition $|n \rangle \to |m \rangle$ between energy
eigenstates of an open quantum system by observing the emission of a photon of
Bohr frequency $\omega_{mn} = (E_n-E_m) / \hbar$. In addition to the
"collapses" to the state $|m\rangle$, the measurement must also have brought
into existence the pre-measurement state $|n \rangle$. As quantum trajectories
are based on past observations, the condition state will jump to $| m \rangle$,
but the state $|n\rangle$ does not feature in any essential way. We resolve

## On the modular operator of mutli-component regions in chiral CFT. (arXiv:1904.08201v1 [hep-th])

We introduce an approach to find the Tomita-Takesaki modular flow for
multi-component regions in chiral conformal field theory. Our method is based
only locality (or braid-relations) of primary fields and the so-called
Kubo-Martin-Schwinger (KMS) condition. These methods can be used to transform
the problem to a Riemann-Hilbert problem on a covering of the complex plane cut
along the regions. The method for instance gives a formula for the modular flow
in the case of a thermal state for the free fermion net, but is in principle

## Confined Quasiparticle Dynamics in Long-Range Interacting Quantum Spin Chains. (arXiv:1810.02365v2 [cond-mat.quant-gas] UPDATED)

We study the quasiparticle excitation and quench dynamics of the
one-dimensional transverse-field Ising model with power-law ($1/r^{\alpha}$)
interactions. We find that long-range interactions give rise to a confining
potential, which couples pairs of domain walls (kinks) into bound
quasiparticles, analogous to mesonic bound states in high-energy physics. We
show that these quasiparticles have signatures in the dynamics of order
parameters following a global quench and the Fourier spectrum of these order

## Simultaneous structures in convex signal recovery - revisiting the convex combination of norms. (arXiv:1904.07893v1 [cs.IT])

In compressed sensing one uses known structures of otherwise unknown signals
to recover them from as few linear observations as possible. The structure
comes in form of some compressibility including different notions of sparsity
and low rankness. In many cases convex relaxations allow to efficiently solve
the inverse problems using standard convex solvers at almost-optimal sampling
rates. A standard practice to account for multiple simultaneous structures in