We present work on a cavity-driven QED system combining an asymmetrical Fabry–Perot cavity and N two-level atoms(TLAs)and show the convenience of simplifying from distinguishable atoms to undistinguishable bosons when the atoms are prepared in the same initial state.Such simplification is valid even when the atoms are not prepared in the inphase condition,since any partial in-phase initial state will evolve into the ground state through a relaxation process.Thus,we get a reduced group of differential equations by introducing the Dicke states,and the under-zero Lyapunov exponents verify its stability.We also work out the collective unconventional photon blockade(UCPB)and get two kinds of giant nonreciprocal UCPBs(NUCPBs)in the weak-driving approximation.Results show that we can employ N noninteracting bosonic atoms to generate a collective UCPB instead of a monoatomic UCPB as the UCPB conditions do not vary with the number of atoms.Furthermore,the forward giant NUCPB only occurring for N larger than a certain number as well as the backward giant NUCPB are controllable by the cavity asymmetry and by the number of atoms.Our findings suggest a prospective approach to the generation of quantum nonreciprocity by N identical atoms.
Unconventional antiferromagnets(AFMs)with non-relativistic spin-splitting,such as the recently discovered altermagnet,have recently gained significant interest due to their potential for novel quantum phenomena and spintronic applications.The compensated magnetization in unconventional AFMs is protected by spin-space symmetries.In this work,we explore the symmetrybreaking effects and identify three distinct mechanisms for inducing net spin magnetizations in unconventional AFMs with collinear or non-collinear spins:(1)finite size effect,(2)extrinsic spin canting effect,and(3)irradiation with circularly polarized light.We show that the induced spin magnetizations are controllable and manifest as diverse intriguing phenomena.For the finite size system,the confined direction of a two-dimensional AM creates quantum-well-like subbands that determine the spin magnetization.This effect can be experimentally probed by measuring the spin density of states and the spin-polarization of Andreev-bound states within planar Josephson junctions.In the case of spin canting effect,it leads to peculiar anisotropic and non-monotonic behaviors in the superconducting proximity effect.Lastly,with circularly polarized light,spin magnetization is driven by the polarized light and the chirality of non-collinear magnetic order,thus offering a direct means of detecting the chirality of magnetic order in real materials.Our findings provide valuable insight into understanding and probing the spin magnetization in unconventional AFM materials.
Although cell-cycle arrest,senescence,and apoptosis are well accepted as the classic barriers in tumorigenesis,recent studies indicate that metabolic regulation is equally important as a major checkpoint in cancer development.It is well accepted that ferroptosis,an iron-dependent programmed cell death,acts as a new type of tumor suppression mechanism tightly linked with numerous metabolic pathways.SLC7A11 is a transmembrane cystine/glutamate transporter protein that plays a vital role in controlling ferroptosis in vivo.The levels of SLC7A11 are dynamically regulated by various types of stresses,such as oxidative stress,nutrient deprivation,endoplasmic reticulum stress,radiation,oncogenic stress,DNA damage,and immune stress.SLC7A11 can be transcriptionally regulated by both activators such as ATF4,NRF2,and ETS1,and repressors including BACH1,p53,ATF3,and STAT1 during stress responses.Moreover,SLC7A11 activity and its protein stability and cellular localization are also modulated upon stress.Patients’data show that SLC7A11 is overexpressed in various types of human cancers,and higher levels of SLC7A11 predict poorer overall survival.Growing evidence also suggests that targeting SLC7A11 is a promising approach in cancer therapy by effectively inhibiting tumor proliferation,invasion,and metastasis,as well as counteracting cancer stem cells and overcoming chemoresistance.This review highlights the regulation of SLC7A11 as an unconventional checkpoint in tumorigenesis through modulating ferroptotic responses under various types of stress.
