# All

## Time-dependent Hamiltonian simulation with $L^1$-norm scaling. (arXiv:1906.07115v1 [quant-ph])

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

## Robust Weyl points in a 1D superlattice with transverse spin-orbit coupling. (arXiv:1906.06820v1 [cond-mat.quant-gas])

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

## Photon position eigenvectors, Wigner's little group and Berry's phase. (arXiv:1709.04884v2 [quant-ph] UPDATED)

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

## Distance scaling and polarization of electric-field noise in a surface ion trap. (arXiv:1906.06489v1 [quant-ph])

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