It has been shown that for nonlinear atomic ionization, transfer of the degree of circular polarization from incident to fluorescence light is maximum at the Cooper minimum (see Phys. Rev. A 100, 011401(R) (2019)). Until the present, however, it is still a challenge to produce and detect circularly-polarized light at xuv and x-ray photon energies. We here show, that transfer of linear polarization

We study the quantum critical effect enhanced spin-nematic squeezing and quantum Fisher information (QFI) in the spin-1 dipolar atomic Bose-Einstein condensate. We show that the quantum phase transitions can improve the squeezing and QFI in the nearby regime of critical point, and the Heisenberg-limited high-precision metrology can be obtained. The different properties of the ground squeeing and entanglement

Entanglement of formation is a fundamental measure that quantifies the entanglement of bipartite quantum states. This measure has recently been extended into multipartite states taking the name α-entanglement of formation. In this work, we follow an analogous multipartite extension for the Gaussian version of entanglement of formation, and focusing on the the finest partition of a multipartite Gaussian

We demonstrate a method to determine the position of single atoms in a three-dimensional optical lattice. Atoms are sparsely loaded from a far-off-resonant optical tweezer into a few vertical planes of a cubic optical lattice positioned near a high-resolution microscope objective. In a single realization of the experiment, we pin the atoms in deep lattices and then acquire multiple fluorescence images

Understanding the effect of interactions in the phase evolution of expanding atomic Bose Einstein condensates is fundamental to describe the basic phenomenon of matter wave interference. Many theoretical and experimental works tackled this problem, always with the implicit assumption that the mutual interaction between two expanding condensates rigidly modifies the phase evolution through an effective

In this work, we experimentally study the angle-dependent single ionization of carbon dioxide (CO2) by linearly and circularly polarized pulses. The angle dependence of the ionization probability by linearly polarized pulses extracted from time-domain measurements on an impulsively-excited rotational wave-packet is compared with data obtained from a direct angle-scan measurement. The results from the

We propose a method for slowing particles by laser fields that potentially has the ability to generate large forces without the associated momentum diffusion that results from the random directions of spontaneously scattered photons. In this method, time-resolved laser pulses with periodically modified detunings address an ultranarrow electronic transition to reduce the particle momentum through repeated

We experimentally examined the propagation of a Gaussian-shaped temporal pulse through a serial array of ring resonators, truncating the pulse before its peak. We observed the process whereby a smooth pulse peak related to the Gaussian pulse emerged even when the incident pulse was truncated before its peak, as the pulse passed through an increasing number of ring resonators. The peak emerged when

Authenticated teleportation aims to certify the transmission of a quantum state through teleportation, even in the presence of an adversary. This scenario can be pictured in terms of an untrusted source distributing a Bell state between two parties who wish to verify it using some simple tests. We propose a protocol that achieves this goal in a practical way, and analyse its performance and security

We perform a systematic investigation of variational forms (wave function Ans"atze), to determine the ground state energies and properties of two-dimensional model fermionic systems on triangular lattices (with and without periodic boundary conditions), using the Variational Quantum Eigensolver (VQE) algorithm. In particular, we focus on the nature of the entangler blocks which provide the most efficient

Anisotropic distributions of the Lyman-α1 transition of the down-charged Xe53+* ions are observed in fast Xe54+ with Kr and Xe collisions, in which the electron is transferred by the non-radiative electron capture mechanism. At the energy of 95 MeV/u, the alignment parameter of the projectile 2p3/2 state, 𝒜20, is determined to be –0.35$0.02forbothtargets.Whiletheprojectileenergyis146MeV/u,thepara

We demonstrate a cryogenic buffer gas-cooled molecular beam source capable of producing bright, continuous beams of cold and slow free radicals via laser ablation over durations of up to 60 seconds. The source design uses a closed liquid helium reservoir as a large thermal mass to minimize heating and ensure reproducible beam properties during operation. Under typical conditions, the source produces

We propose a scheme that generalizes the loss scaling properties of twin-field or phase-matching QKD related to a channel of transmission ηtotal from ηtotal to ηtotal2n by employing n−1 memory stations with spin qubits and n beam-splitter stations including optical detectors. Our scheme’s resource states are similar to the coherent-state-based light-matter entangled states of a previous hybrid quantum

We propose a method to realize the Frenkel-Kontorova model using an array of Rydberg dressed atoms. Our platform can be used to study this model with a range of realistic interatomic potentials. In particular, we concentrate on two types of interaction potentials: a springlike potential and a repulsive long-range potential. We numerically calculate the phase diagram for such systems and characterize

Quantifying nonclassicality of a bosonic mode is an important but challenge task in quantum optics. Recently, the first nonclassicality measure based on the concept of operational resource theory has been proposed [Phys. Rev. Research 2, 023400 (2020)], which shows several crucial properties as a resource for quantum metrology. Here we apply the measure to evaluate and categorize different classes

An ultradilute quantum droplet is a self-bound liquid-like state recently observed in ultracold Bose-Einstein condensates. In most previous theoretical studies, it is described by a phenomenological low-energy effective theory, termed as the extended GrossPitaevskii equation. Here, we microscopically derive the GrossPitaevskii equation for the condensate and also for a pairing field in an inhomogeneous

We develop a general approach for calculating the characteristic function of the work distribution of we use the determinant representation of the many-body wave function to characterise the nonequilibrium thermodynamics of the TG gas and obtain exact and computationally tractable expressions—in terms of Fredholm determinants—for the mean work, the work probability distribution function, the nonadiabaticity

The negative ion of lanthanum, La−, has one of the richest bound state spectra observed for an atomic negative ion and has been proposed as a promising candidate for laser-cooling applications. In the present experiments, La− was investigated using tunable infrared photodetachment spectroscopy. The relative signal for neutral atom production was measured with a crossed ion-beam–laser-beam apparatus

In this paper we develop a theory for the first and second sound in a two-dimensional atomic gas across the superfluid transition based on the dynamic Koterlitz-Thouless theory. We employ a set of modified two-fluid hydrodynamic equations which incorporate the dynamics of the quantised vortices, rather than the conventional ones for a three-dimensional superfluid. As far as the sound dispersion equation

Supersolidity – a coexistence of superfluidity and crystalline or amorphous density variations – has been vividly debated ever since its conjecture. While the initial focus was on helium-4, recent experiments uncovered supersolidity in ultra-cold dipolar quantum gases. Here, we propose a new self-bound supersolid phase in a binary mixture of Bose gases with short-range interactions, making use of the

We consider the space of n×n non-Hermitian Hamiltonians (n=2, 3, ...) that are equivalent to a single n×n Jordan block. We focus on adiabatic transport around a closed path (i.e., a loop) within this space, in the limit as the time scale T=1/ɛ taken to traverse the loop tends to infinity. We show that, for a certain class of loops and a choice of initial state, the state returns to itself and acquires

The dynamics of systems with higher-order dispersion are rapidly advancing to the center of modern hydrodynamics research. From natural shallow water waves and nonlinear optics, to manufactured microcavity resonators, these systems offer many surprises that motivate both fundamental insights as well as new device paradigms. An extreme regime of hydrodynamics is the formation of shock waves, where nonlinearities

Non-equilibrium photon correlations of coherently excited single quantum systems can reveal their internal quantum dynamics and provide spectroscopic access. Here we propose and discuss the fundamentals of a coherent photon coincidence spectroscopy based on the application of laser pulses with variable delay and the detection of a time-averaged two-photon coincidence rate. For demonstration, two simple

We derive an exact description of the non-equilibrium dynamics at finite temperature for the anyonic Tonks-Girardeau gas extending the results of Atas {et al.} [Phys. Rev. A 95 , 043622 (2017)] to the case of arbitrary statistics. The one-particle reduced density matrix is expressed as the Fredholm minor of an integral operator with the kernel being the one-particle Green’s function of free fermions

We present a theoretical study of atomic laser-assisted photoionization emission (LAPE). We consider an atom driven by a linearly polarized XUV laser in two different scenarios: i) a single attosecond pulse (in both the streaking and sideband regimes) and ii) an attosecond pulse train. The process takes place assisted by a linearly polarized infrared (IR) laser field. In all these cases the energy

We investigate the effects of static electric and magnetic fields on the differential ac Stark shifts for microwave transitions in ultracold bosonic 87Rb133Cs molecules, for light of wavelength λ=1064nm. Near this wavelength we observe unexpected two-photon transitions that may cause trap loss. We measure the ac Stark effect in external magnetic and electric fields, using microwave spectroscopy of

We investigate thermophonon transports and its nontrivial Berry-phase-like effect in an optomechanical system with squeezed vacuum injection. By taking the cumulant generating function approach that allows for analytical derivations of the thermophonon flux and the Berry curvature. Further, the quantum master equation approach is invoked to verify the analytical results of the transport properties

We show that the standard method of introducing the quantum description of the electromagnetic field – by canonical field quantization – is not the only one. We have chosen here the relativistic quantum mechanics of the photon as the starting point. The treatment of photons as elementary particles merges smoothly with the description in terms of the quantized electromagnetic field but it also reveals

The tight connection between mass and energy unveiled by Special Relativity, summarized by the iconic formula E=mc2, has revolutionized our understanding of nature and even shaped our political world over the past century through its military application. It is certainly one of the most exhaustively-tested and well-known equations of modern science. Although we have become used to its most obvious

Ultradilute quantum droplets are intriguing new state of matter, in which the attractive mean-field force can be balanced by the repulsive force from quantum fluctuations to avoid collapse. Here, we present a microscopic theory of ultradilute quantum droplets in three-, one- and two-dimensional two-component Bose-Bose mixtures, by generalizing the conventional Bogoliubov theory to include the bosonic

We address the properties of continuous-time quantum walks with Hamiltonians of the form ℋ=L+λL2, being L the Laplacian matrix of the underlying graph and being the perturbation λL2 motivated by its potential use to introduce next-nearest-neighbor hopping. We consider cycle, complete, and star graphs because paradigmatic models with low/high connectivity and/or symmetry. First, we investigate the dynamics

We formulate an exact spacetime mapping between the 𝒩-point correlation functions of two different experiments with open quantum gases. Our formalism extends a quantum-field mapping result for closed systems [Phys. Rev. A 94, 043628 (2016)] to the general case of open quantum systems with Markovian property. For this, we consider an open many-body system consisting of a D-dimensional quantum gas of