Phase distortions, or aberrations, can negatively influence the performance

of an optical imaging system. Through the use of position-momentum entangled

photons, we nonlocally correct for aberrations in one photon's optical path by

intentionally introducing the complementary aberrations in the optical path of

the other photon. In particular, we demonstrate the simultaneous nonlocal

cancellation of aberrations that are of both even and odd order in the photons'

# All

Two-dimensional Nuclear Magnetic Resonance (NMR) is essential in molecular

structure determination. The Nitrogen-Vacancy (NV) center in diamond has been

proposed and developed as an outstanding quantum sensor to realize NMR in

nanoscale. In this work, we develop a scheme for two-dimensional nanoscale NMR

spectroscopy based on quantum controls on an NV center. We carry out a proof of

principle experiment on a target of two coupled $^{13}$C nuclear spins in

diamond. A COSY-like sequences is used to acquire the data on time domain,

Recent years have witnessed a growing interest in topics at the intersection

of many-body physics and complexity theory. Many-body physics aims to

understand and classify emergent behavior of systems with a large number of

particles, while complexity theory aims to classify computational problems

based on how the time required to solve the problem scales as the problem size

becomes large. In this work, we use insights from complexity theory to classify

phases in interacting many-body systems. Specifically, we demonstrate a

Deployment of quantum technology in space provides opportunities for new

types of precision tests of gravity. On the other hand, the operational demands

of such technology can make previously unimportant effects practically

relevant. We describe a novel optical interferometric red-shift measurement and

a measurement scheme designed to witness possible spin-gravity coupling

effects.

EPR-steering refers to the ability of one observer to convince a distant

observer that they share entanglement by making local measurements. Determining

which states allow a demonstration of EPR-steering remains an open problem in

general, even for the simplest case of two qubits. Here, we outline and

demonstrate a method of constructing new classes of two-qubit states which are

non-steerable by arbitrary projective measurements, from consideration of local

The Riemann hypothesis, one of the most important open problems in pure

mathematics, implies the most profound secret of prime numbers. One of the most

interesting approaches to solve this hypothesis is to connect the problem with

the spectrum of the physical Hamiltonian of a quantum system. However, none of

the proposed quantum Hamiltonians have been experimentally feasible. Here, we

report the first experiment to identify the first non-trivial zeros of the

We analyze the class of Generalized Double Semion (GDS) models in arbitrary

dimensions from the point of view of lattice Hamiltonians. We show that on a

$d$-dimensional spatial manifold $M$ the dual of the GDS is equivalent, up to

constant depth local quantum circuits, to a group cohomology theory tensored

with lower dimensional cohomology models that depend on the manifold $M$. We

comment on the space-time topological quantum field theory (TQFT)

interpretation of this result. We also investigate the GDS in the presence of

The fast forward scheme of adiabatic quantum dynamics is applied to finite

regular spin clusters with various geometries and the nature of driving

interactions is elucidated. The fast forward is the quasi-adiabatic dynamics

guaranteed by regularization terms added to the reference Hamiltonian, followed

by a rescaling of time with use of a large scaling factor. With help of the

regularization terms consisting of pair-wise and 3-body interactions, we apply

the proposed formula (Phys. Rev.A 96, 052106(2017)) to regular triangle and

The properties of ground state of spin-$\frac{1}{2}$ kagome antiferromagnetic

Heisenberg (KAFH) model have attracted considerable interest in the past few

decades, and recent numerical simulations reported a spin liquid phase. The

nature of the spin liquid phase remains unclear. For instance, the interplay

between symmetries and $Z_2$ topological order leads to different types of

$Z_2$ spin liquid phases. In this paper, we develop a numerical simulation

method based on symmetric projected entangled-pair states (PEPS), which is

For quantum communications, the use of Earth-orbiting satellites to extend

distances has gained significant attention in recent years, exemplified in

particular by the launch of the Micius satellite in 2016. The performance of

applied protocols such as quantum key distribution (QKD) depends significantly

upon the transmission efficiency that can be achieved through the turbulent

atmosphere, which is especially challenging for ground-to-satellite uplink

scenarios. Adaptive optics (AO) techniques have been used in astronomical,