Optical-Microwave Entanglement Paves the Way for Distributed Quantum Computation

Over the past few years,quantum computation based on superconducting circuits has achieved remarkable progress.A milestone occurred in 2019 when Google released Sycamore,a processor with 54 qubits,and claimed quantum supremacy by performing in just 100 s a specific computation which would take a classical supercomputer,as stated by Google’s team,10000 years to complete.[1]In 2021,a strong quantum advantage was demonstrated by Pan and his colleagues from the University of Science and Technology of China,using a quantum processor named Zuchongzhi,which has 66 functional qubits.[2]This year,the record of the number of quantum qubits has been lifted to 127 qubits.[3]Indeed,the number of qubits is limited to a few hundreds due to the finite space of dilution refrigerators,where the superconducting qubits must be placed to be isolated from thermal noise.However,this number is still several orders of magnitude away from the requirement of quantum error correction,which is essential for general-purpose quantum computers.[4–8].

Coupling ideality of standing-wave supermode microresonators

Standing-wave supermode microresonators that are created through the strong coupling between counter-propagating modes have emerged as versatile platforms for sensing and nonlinear optics.For example,these microresonators have shown potential in nanoparticle sizing and counting,as well as enhancing the single-photon optomechanical coupling rate of stimulated Brillouin scattering.However,it has been observed that the relation between the mode linewidth and on-resonance transmission of the split supermodes differs obviously from that of the non-split modes.This behavior is typically quantified by the coupling ideality(I),which remains inadequately explored for the standing-wave supermodes.In this study,we theoretically and experimentally investigate the coupling ideality of standing-wave supermodes in a commonly employed configuration involving a Si O2microresonator side-coupled to a tapered fiber.Our findings demonstrate that,even with a single-mode tapered fiber,the coupling ideality of the standing-wave supermodes is limited to 0.5,due to the strong backscattering-induced energy loss into the counter-propagating direction,resulting in an additional equivalent parasitic loss.While achieving a coupling ideality of 0.5 presents challenges for reaching over-coupled regimes,it offers a convenient approach for adjusting the total linewidth of the modes while maintaining critically-coupled conditions.

Micropascal-sensitivity ultrasound sensors based on optical microcavities

Whispering gallery mode(WGM)microcavities have been widely used for high-sensitivity ultrasound detection,owing to their optical and mechanical dual-resonance enhanced sensitivity.The ultrasound sensitivity of the cavity optomechanical system is fundamentally limited by thermal noise.In this work,we theoretically and experimentally investigate the thermal-noise-limited sensitivity of a WGM microdisk ultrasound sensor and optimize the sensitivity by varying the radius and a thickness of the microdisk,as well as using a trench structure around the disk.Utilizing a microdisk with a radius of 300μm and thickness of 2μm,we achieve a peak sensitivity of 1.18μPa Hz^(-1/2)at 82.6 k Hz.To the best of our knowledge,this represents the record sensitivity among cavity optomechanical ultrasound sensors.Such high sensitivity has the potential to improve the detection range of air-coupled ultrasound sensing technology.

Free spectral range magnetic tuning of an integrated microcavity

Tunable whispering-gallery-mode(WGM)microcavities are promising devices for reconfigurable photonic applications such as widely tunable integrated lasers and reconfigurable optical filters for optical communication and information processing.Scaling up these devices demands the ability to tune the optical resonances in an integrated manner over a full free spectral range(FSR).Here we propose a high-speed full FSR magnetic tuning scheme of an integrated silicon nitride(Si_(3)N_(4))double-disk microcavity.By coating a magnetostrictive film on the spokes and the central pad of the Si_(3)N_(4) cavity,magnetic tuning can be realized using a microcoil integrated on the same chip.An FSR tuning can be achieved by combining magnetostrictive strain with strong optomechanical interactions provided by the double-disk microcavity.We calculate the required magnetic flux density to tune an FSR(B_(FSR))as a function of several key geometric parameters,including the air gap,radius,width of the spokes and ring of the double-disk cavities,as well as the thickness of the magnetostrictive film.The proposed structure enables a full FSR tuning with a required magnetic flux density of milli-Tesla(mT)level.We also study the dynamic response of the integrated device with an alternating current(AC)magnetic field driving,and find that the tuning speed can reach hundreds of kHz in the air.

Identification of a PP2A gene in Bombyx mori with antiviral function against B.mori nucleopolyhedrovirus

Ser/Thr protein phosphatase 2A(PP2A)is one of the type 2 protein phosphatases,which is required for many intracellular physiological processes and pathogen infection.However,the function of PP2A is unclear in silkworm,Bombyx mori.Here,we cloned and identified BmPP2A,a PP2A gene from B.mori,which has two HEAT domains and a high similarity to PP2A from other organisms.Our results showed that BmPP2A is localized in the cytoplasm and highly expressed in silkworm epidermis and midgut,and that Bombyx mori nucleopolyhedrovirus(BmNPV)infection induces down-regulation of BmPP2A expression.Furthermore,up-regulation of BmPP2A via overexpression significantly inhibited BmNPV multiplication.In contrast,down-regulation of BmPP2A via RNA interference and okadaic acid(a PP2A inhibitor)treatment allowed robust BmNPV replication.This is the first report of PP2A having an antiviral effect in silkworm and provides insights into the function of BmPP2A,a potential anti-BmNPV mechanism,and a possible target for the breeding of silkworm-resistant strains.

Targeted inhibition of myeloid-derived suppressor cells in the tumor microenvironment by low-dose doxorubicin to improve immune efficacy in murine neuroblastoma

Background:High agglomeration of myeloid-derived suppressor cells(MDSCs)in neuroblastoma(NB)impeded therapeutic effects.This study aimed to investigate the role and mechanism of targeted inhibition of MDSCs by low-dose doxorubicin(DOX)to enhance immune efficacy in NB.Methods:Bagg albino(BALB/c)mice were used as tumor-bearing mouse models by injecting Neuro-2a cells,and MDSCs were eliminated by DOX or dopamine(DA)administration.Tumor-bearing mice were randomly divided into 2.5 mg/kg DOX,5.0 mg/kg DOX,50.0 mg/kg DA,and control groups(n=20).The optimal drug and its concentration for MDSC inhibition were selected according to tumor inhibition.NB antigen-specific cytotoxic T cells(CTLs)were prepared.Tumor-bearing mice were randomly divided into DOX,CTL,anti-ganglioside(GD2),DOX+CTL,DOX+anti-GD2,and control groups.Following low-dose DOX administration,immunotherapy was applied.The levels of human leukocyte antigen(HLA)-I,CD8,interleukin(IL)-2 and interferon(IFN)-γin peripheral blood,CTLs,T-helper 1(Th1)/Th2 cytokines,perforin,granzyme and tumor growth were compared among the groups.The Wilcoxon two-sample test and repeated-measures analysis of variance were used to analyze results.Results:The slowest tumor growth(F=6.095,P=0.018)and strongest MDSC inhibition(F=14.632,P=0.001)were observed in 2.5 mg/kg DOX group.Proliferation of T cells was increased(F=448.721,P<0.001)and then decreased(F=2.047,P=0.186).After low-dose DOX administration,HLA-I(F=222.489),CD8(F=271.686),Th1/Th2 cytokines,CD4^(+)and CD8^(+)lymphocytes,granzyme(F=2376.475)and perforin(F=488.531)in tumor,IL-2(F=62.951)and IFN-γ(F=240.709)in peripheral blood of each immunotherapy group were all higher compared with the control group(all ofP values<0.05).The most significant increases in the aforementioned indexes and the most notable tumor growth inhibition were observed in DOX+anti-GD2 and DOX+CTL groups.Conclusions:Low-dose DOX can be used as a potent immunomodulatory agent that selectively impairs MDSC-induced immunosuppression,thereby fostering immune efficacy in NB.

Continuum damage mechanics based modeling progressive failure of woven-fabric composite laminate under low velocity impact

A continuum damage mechanics (CDM) meso-model was derived for both intraply and interply progressive failure behaviors of a 2D woven-fabric composite laminate under a transversely low velocity impact.An in-plane anisotropic damage constitutive model of a 2D woven composite ply was derived based on CDM within a thermodynamic framework,an elastic constitutive model with damage for the fibre directions and an elastic-plastic constitutive model with damage for the shear direction.The progressive failure behavior of a 2D woven composite ply is determined by the damage internal variables in different directions with appropriate damage evolution equations.The interface between two adjacent 2D woven composite plies with different ply orientations was modeled by a traction-separation law based interface element.An isotropic damage constitutive law with CDM properties was used for the interface element,and a damage surface which combines stress and fracture mechanics failure criteria was employed to derive the damage initiation and evolution for the mixed-mode delamination of the interface elements.Numerical analysis and experiments were both carried out on a 2D woven glass fibre/epoxy laminate.The simulation results are in agreement with the experimental counterparts,verifying the progressive failure model of a woven composite laminate.The proposed model will enhance the understanding of dynamic deformation and progressive failure behavior of composite laminate structures in the low velocity impact process.