Heteronuclear Magnetisms with Ultracold Spinor Bosonic Gases in Optical Lattices

Motivated by recent realizations of spin-1 NaRb mixtures in the experiments[Phys.Rev.Lett.114,255301(2015);Phys.Rev.Lett.128,223201(2022)],we investigate heteronuclear magnetism in the Mott-insulating regime.Different from the identical mixtures where the boson statistics only admits even parity states from angular momentum composition,for heteronuclear atoms in principle all angular momentum states are allowed,which can give rise to new magnetic phases.While various magnetic phases can be developed over these degenerate spaces,the concrete symmetry breaking phases depend on not only the degree of degeneracy but also the competitions from many-body interactions.We unveil these rich phases using the bosonic dynamical mean-field theory approach.These phases are characterized by various orders,including spontaneous magnetization order,spin magnitude order,singlet pairing order,and nematic order,which may coexist specially in the regime with odd parity.Finally we address the possible parameter regimes for observing these spin-ordered Mott phases.

Study on polyurethane-based porous materials and their adsorption properties

The flexible superhydrophobic thermoplastic polyurethane(TPU)porous material was prepared by heat-induced phase separation method with two cooling steps.The influence of the preparation process on the microstructure of the material was discussed in depth.The microstructure,hydrophobicity and specific surface area of porous TPU materials were analyzed in detail.The surface wettability,separation selectivity,saturated adsorption capacity and adsorption rate,mechanical properties,environmental adaptability and cyclic properties of porous TPU materials were studied.The results show that the TPU-8%porous monolithic material prepared by heat-induced phase separation method shows good performance when the polymer concentration is 8%,the phase separation temperature is 0℃,the phase separation time is 30min,and the mixing solvent ratio is 9:1.

Subdiffraction optical manipulation of the charge state of nitrogen vacancy center in diamond

As a potential candidate for quantum computation and metrology,the nitrogen vacancy(NV)center in diamond presents both challenges and opportunities resulting from charge-state conversion.By utilizing different lasers for the photon-induced charge-state conversion,we achieved subdiffraction charge-state manipulation.The charge-state depletion(CSD)microscopy resolution was improved to 4.1 nm by optimizing the laser pulse sequences.Subsequently,the electron spin-state dynamics of adjacent NV centers were selectively detected via the CSD.The experimental results demonstrated that the CSD can improve the spatial resolution of the measurement of NV centers for nanoscale sensing and quantum information.

A mechanically tuned Kerr comb in a dispersion-engineered silica microbubble resonator

This paper discusses the developement and investigation of a silica microbubble resonator(MBR) that is optimized to cancel mode dispersion with material dispersion, at a wavelength of approximately 1550 nm and maintain a quality factor of an optical mode as large as 5.4 × 10~7. Benefitting from the near-zero dispersion and high quality factor, a primary optical comb is generated in the MBR using cascaded four-wave mixing processes, which span over 300 nm with several tens of teeth. Furthermore, the frequency comb could be gradually tuned by mechanically stretching the MBR. This tunable Kerr comb has multiple potential applications in precision measurements and sensing applications, such as molecular spectroscopy and ranging.

All-optical modulation of quantum states by nonlinear metasurface

Metasurfaces have proven themselves an exotic ability to harness light at nano-scale,being important not only for classical but also for quantum optics.Dynamic manipulation of the quantum states is at the heart of quantum information processing;however,such function has been rarely realized with metasurfaces so far.Here,we report an all-optical dynamic modulation of the photonic quantum states using the nonlinear metasurface.The metasurface consists of a metallic nanostructure combined with a photoisomerizable azo layer.By tuning the plasmonic resonance through optically switching the azo molecules between their binary isomeric states,we have realized dynamic control of transmission efficiencies of orthogonally polarized photons and also the phase delay between them,thereby an entangled state was efficiently controlled.As an illustration,a quantum state distillation has been demonstrated to recover a Bell state from a non-maximally entangled one to that with fidelities higher than 98%.Our work would enrich the functions of the metasurface in the quantum world,from static to dynamic modulation,making the quantum metasurface going practical.

Hertz-rate metropolitan quantum teleportation

Quantum teleportation can transfer an unknown quantum state between distant quantum nodes,which holds great promise in enabling large-scale quantum networks.To advance the full potential of quantum teleportation,quantum states must be faithfully transferred at a high rate over long distance.Despite recent impressive advances,a high-rate quantum teleportation system across metropolitan fiber networks is extremely desired.Here,we demonstrate a quantum teleportation system which transfers quantum states carried by independent photons at a rate of 7.1±0.4 Hz over 64-km-long fiber channel.An average single-photon fidelity of≥90.6±2.6%is achieved,which exceeds the maximum fidelity of 2/3 in classical regime.Our result marks an important milestone towards quantum networks and opens the door to exploring quantum entanglement based informatic applications for the future quantum internet.

Correlated spectrum of distant semiconductor qubits coupled by microwave photons

We develop a new spectroscopic method to quickly and intuitively characterize the coupling of two microwave-photon-coupled semiconductor qubits via a high-impedance resonator.Highly distinctive and unique geometric patterns are revealed as we tune the qubit tunnel couplings relative to the frequency of the mediating photons.These patterns are in excellent agreement with a simulation using the Tavis-Cummings model,and allow us to readily identify different parameter regimes for both qubits in the detuning space.This method could potentially be an important component in the overall spectroscopic toolbox for quickly characterizing certain collective properties of multiple cavity quantum electrodynamics(QED)coupled qubits.

Fabrication,testing,and assembly of high-finesse optical fiber microcavity for molecule cavity QED experiment

The ultracold molecule is a promising candidate for versatile quantum tasks due to its long-range interaction and rich internal rovibrational states.With the help of the cavity quantum electrodynamics(QED)effects,an optical cavity can be employed to increase the efficiency of the formation of the photoassociated molecules and offers a non-demolition detection of the internal states of molecules.Here,we demonstrate the production of the high-finesse optical fiber microcavity for the Rb_(2) molecule cavity QED experiment,which includes the fabrication of fiber-based cavity mirrors,testing,and the assembly of ultra-high vacuum-compatible optical fiber microcavity.The optical fiber microcavity offers high cooperativity between cavity mode and ultracold molecule and paves the way for the study of molecule cavity QED experimental research.

Electric Field Measurement and Application Based on Rydberg Atoms

Microwave sensing offers important applications in areas such as data communication and remote sensing.It has thus received much attention from academia,industry,and governments.Atomic wireless sensing uses the strong response of the large electric dipole moment of a Rydberg atom in response to an external field to achieve precise measurement of a radio frequency(RF)signal.This method offers advantages over traditional wireless sensing including ultrawide energy level transitions,which makes it responsive to RF electric fields over a wide bandwidth.Here,we briefly review the progress of electric field measurement based on Rydberg atoms.We discuss the properties of Rydberg atoms,measurement using Rydberg atoms,experimental progress in electric field measurement of different bands,and different methods for detecting electric fields(such as atomic superheterodyne,machine learning,and critically enhanced measurement).The development of Rydberg atomic measurement focuses on the advantages of Rydberg atomic sensing,especially when compared to conventional microwave receivers.This work is of major significance to developing Rydberg-based measurements in astronomy,remote sensing,and other fields.

Effect of unbalanced and common losses in quantum photonic integrated circuits

Loss is inevitable for the optical system due to the absorption of materials, scattering caused by the defects, and surface roughness. In quantum optical circuits, the loss can not only reduce the intensity of the signal, but also affect the performance of quantum operations. In this work, we divide losses into unbalanced linear losses and shared common losses, and provide a detailed analysis on how loss affects the integrated linear optical quantum gates. It is found that the orthogonality of eigenmodes and the unitary phase relation of the coupled waveguide modes are destroyed by the loss. As a result, the fidelity of single-and two-qubit operations decreases significantly as the shared loss becomes comparable to the coupling strength. Our results are important for the investigation of large-scale photonic integrated quantum information processes.

Generalized Kibble-Zurek mechanism for defects formation in trapped ions

The Kibble-Zurek(KZ)mechanism has played a fundamental role in defect formation with universal scaling laws in nonequilibrium phase transitions.However,this theory may not accurately predict the scaling laws in inhomogeneous systems and slow quenching processes.Here,we present a generalized KZ mechanism for the defect formation in trapped ions with the freeze-out condition gt=b0τ(t),where g is a universal quenching velocity function and b0 is a constant.We derived a differential equationφ(x,t)to account for the frozen correlation length of a kink in an inhomogeneous system and demonstrated a smooth crossover from a fast quenching process to a slow quenching process,which agrees well with the experiments performed by Ulm et al.[Nat.Commun.4,2290(2013)]and Pyka et al.[Nat.Commun.4,2291(2013)].Furthermore,we confirmed our theoretical model using molecular dynamics simulation by solving the stochastic differential equation,showing excellent agreement with the results from the differential equation.Our theory provides a general theoretical framework for studying KZ physics in inhomogeneous systems,which has applications in other nonequilibrium platforms studied experimentally.

Silicon photonic devices for scalable quantum information applications

With high integration density and excellent optical properties, silicon photonics is becoming a promising platform for complete integration and large-scale optical quantum information processing. Scalable quantum information applications need photon generation and detection to be integrated on the same chip, and we have seen that various devices on the silicon photonic chip have been developed for this goal. This paper reviews the relevant research results and state-of-the-art technologies on the silicon photonic chip for scalable quantum applications. Despite the shortcomings, the properties of some components have already met the requirements for further expansion. Furthermore, we point out the challenges ahead and future research directions for on-chip scalable quantum information applications.