The difficulty of simulating quantum dynamics depends on the norm of the

Hamiltonian. When the Hamiltonian varies with time, the simulation complexity

should only depend on this quantity instantaneously. We develop quantum

simulation algorithms that exploit this intuition. For the case of sparse

Hamiltonian simulation, the gate complexity scales with the $L^1$ norm

$\int_{0}^{t}\mathrm{d}\tau\left\lVert H(\tau)\right\lVert_{\max}$, whereas the

best previous results scale with $t\max_{\tau\in[0,t]}\left\lVert

# All

We show that the cylindrical symmetry of the eigenvectors of the photon

position operator with commuting components, x, reflects the E(2) symmetry of

the photon little group. The eigenvectors of x form a basis of localized states

that have definite angular momentum, J, parallel to their common axis of

symmetry. This basis is well suited to the description of "twisted light" that

has been the subject of many recent experiments and calculations. Rotation of

the axis of symmetry of this basis results in the observed Berry phase

We study quantum anomaly detection with density estimation and multivariate

Gaussian distribution. Both algorithms are constructed using the standard

gate-based model of quantum computing. Compared with the corresponding

classical algorithms, the resource complexities of our quantum algorithm are

logarithmic in the dimensionality of quantum states and the number of training

quantum states. We also present a quantum procedure for efficiently estimating

the determinant of any Hermitian operators $\mathcal{A}\in\mathcal{R}^{N\times

Weyl points, synthetic magnetic monopoles in the 3D momentum space, are the

key features of topological Weyl semimetals. The observation of Weyl points in

ultracold atomic gases usually relies on the realization of high-dimensional

spin-orbit coupling (SOC) for two pseudospin states (% \textit{i.e.,}

spin-1/2), which requires complex laser configurations and precise control of

laser parameters, thus has not been realized in experiment. Here we propose

that robust Wely points can be realized using 1D triple-well superlattices

We probe electric-field noise in a surface ion trap for ion-surface distances

$d$ between 50 and 300 $\mu\mathrm{m}$ in the normal and planar directions. We

find the noise distance dependence to scale as $d^{-2.6}$ in our trap and a

frequency dependence which is consistent with $1/f$ noise. Simulations of the

electric-field noise specific to our trap geometry provide evidence that we are

not limited by technical noise sources. Our distance scaling data is consistent

The vast and growing number of publications in all disciplines of science

cannot be comprehended by a single human researcher. As a consequence,

researchers have to specialize in narrow sub-disciplines, which makes it

challenging to uncover scientific connections beyond the own field of research.

Thus access to structured knowledge from a large corpus of publications could

help pushing the frontiers of science. Here we demonstrate a method to build a

semantic network from published scientific literature, which we call SemNet. We

Mechanical modes are a potentially useful resource for quantum information

applications, such as quantum-level wavelength transducers, due to their

ability to interact with electromagnetic radiation across the spectrum. A

significant challenge for wavelength transducers is thermomechanical noise in

the mechanical mode, which pollutes the transduced signal with thermal states.

In this paper, we eliminate thermomechanical noise in the GHz-frequency

mechanical breathing mode of a piezoelectric optomechanical crystal using

Generalising the concept of Bell nonlocality to networks leads to novel forms

of correlations, the characterization of which is however challenging. Here we

investigate constraints on correlations in networks under the two natural

assumptions of no-signaling and independence of the sources. We consider the

``triangle network'', and derive strong constraints on correlations even though

the parties receive no input, i.e. each party performs a fixed measurement. We

Two time-reversal quantum key distribution (QKD) schemes are the quantum

entanglement based device-independent (DI)-QKD and

measurement-device-independent (MDI)-QKD. The recently proposed twin field

(TF)-QKD, also known as phase-matching (PM)-QKD, has improved the key rate

bound from $O\left( \eta \right )$ to $O\left( \sqrt {\eta} \right )$ with

$\eta$ the channel transmittance. In fact, TF-QKD is a kind of MDI-QKD but

based on single-photon detection. In this paper, we propose a different PM-QKD

We address the standard quantum error correction using the three-qubit

bit-flip code, yet in continuous-time. This entails rendering a target manifold

of quantum states globally attractive. Previous feedback designs could feature

spurious equilibria, or resort to discrete kicks pushing the system away from

these equilibria to ensure global asymptotic stability. We present a new

approach that consists of introducing controls driven by Brownian motions.