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Quantum phases of self-bound droplets of Bose-Bose mixtures

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arXiv 2021年

作者： Pan, Junqiao Yi, Su Shi, Tao CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing100190 China School of Physical Sciences University of Chinese Academy of Sciences Beijing100049 China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing100049 China Shenzhen Institute for Quantum Science and Engineering Southern University of Science and Technology Shenzhen518055 China

We systematically investigate the ground-state properties of self-bound droplets of quasi-two-dimensional binary Bose gases by using the Gaussian state theory. We find that quantum droplets consists two macroscopic squeezed phases and a macroscopic coherent phase. We map out the phase diagram and determine all phase boundaries via both numerical and nearly analytical methods. In particular, we find three easily accessible signatures for the quantum phases and the stablization mechanism of the self-bound droplets by precisely measuring their radial size. Our studies indicate that binary droplets represent an ideal platform for in-depth investigations of the quantum nature of the droplet state. Copyright © 2021, The Authors. All rights reserved.

关键词： Drops

Ultra-stable tellurium-doped carbon quantum dots for cell protection and near-infrared photodynamic application

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science Bulletin 2020年第18期65卷 1580-1586,M0004页

作者： Hao Chen Kaikai Wen Jingya Chen Wang Xing Xiaoxi Wu Qinqin Shi Aidong Peng Hui Huang Center of Materials Science and Opto-electronic Technology College of Materials Science and Opto-electronic Technology&CAS Center for Excellence in Topological Quantum Computation&CAS Key Laboratory of Vacuum PhysicsUniversity of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Flexible Electronics(KLOFE) Institute of Advanced Materials(1AM)Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)Nanjing Tech UniversityNanjing 211816China

It is important to regulate the concentration of reactive oxygen species(ROS)in cells since they play important roles in ***,developing nanoreagents to control the ROS is ***,tellurium-doped carbon quantum dots(Te-CDs)were developed by a simple and efficient hydrothermal method,which can scavenge H2O2 to protect cells under ambient condition,but generateáOH under 808 nm irradiation as photodynamic *** contribution presented a kind of novel CDs with dual-functions,which can potentially regulate ROS under different conditions.

关键词： Reactive oxygen species regulation Tellurium Carbon quantum dots Scavenge free-radical Photodynamic effect

Topological Spin Texture of Chiral Edge States in Photonic Two-Dimensional Quantum Walks

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arXiv 2021年

作者： Chen, Chao Ding, Xing Qin, Jian Wu, Jizhou He, Yu Lu, Chao-Yang Li, Li Liu, Xiong-Jun Sanders, Barry C. Pan, Jian-Wei Hefei National Laboratory for Physical Sciences at the Microscale Department of Modern Physics University of Science and Technology of China Shanghai Branch Shanghai201315 China CAS-Alibaba Quantum Computing Laboratory CAS Centre for Excellence in Quantum Information and Quantum Physics Shanghai201315 China National Laboratory of Solid State Microstructures School of Physics Nanjing University Nanjing210093 China Shenzhen Institute for Quantum Science and Engineering Southern University of Science and Technology Shenzhen518055 China International Center for Quantum Materials School of Physics Peking University Beijing100871 China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing100190 China Institute for Quantum Science and Technology University of Calgary ABT2N 1N4 Canada

Topological insulators host topology-linked boundary states, whose spin and charge degrees of freedom could be exploited to design topological devices with enhanced functionality. We experimentally observe that dissipationless chiral edge states in a spin-orbit coupled anomalous Floquet topological phase exhibit topological spin texture on boundaries, realized via a two-dimensional quantum walk. Our experiment shows that, for a walker traveling around a closed loop along the boundary in real space, its spin evolves and winds through a great circle on the Bloch sphere, which implies that edge-spin texture has nontrivial winding. This topological spin winding is protected by a chiral-like symmetry emerging for the low-energy Hamiltonian. Our experiment confirms that two-dimensional anomalous Floquet topological systems exhibit topological spin texture on the boundary, which could inspire novel topology-based spintronic phenomena and devices. Copyright © 2021, The Authors. All rights reserved.

关键词： Topology

Variational theory of angulons and their rotational spectroscopy

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arXiv 2022年

作者： Zeng, Zhongda Yakaboylu, Enderalp Lemeshko, Mikhail Shi, Tao Schmidt, Richard Max Planck Institute of Quantum Optics Garching85748 Germany Institute for Theoretical Physics University of Innsbruck InnsbruckA-6020 Austria Institute for Quantum Optics and Quantum Information Austrian Academy of Sciences InnsbruckA-6020 Austria Institute of Science and Technology Austria Am Campus 1 Klosterneuburg3400 Austria CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing100190 China CAS Center for Excellence in Topological Quantum Computation & School of Physical Sciences University of Chinese Academy of Sciences Beijing100049 China Institute for Theoretical Physics Heidelberg University Philosophenweg 16 Heidelberg69120 Germany

The angulon, a quasiparticle formed by a quantum rotor dressed by the excitations of a many-body bath, can be used to describe an impurity rotating in a fluid or solid environment. Here we propose a coherent state ansatz in the co-rotating frame which provides a comprehensive theoretical description of angulons. We reveal the quasiparticle properties, such as energies, quasiparticle weights and spectral functions, and show that our ansatz yields a persistent decrease in the impurity’s rotational constant due to many-body dressing, consistent with experimental observations. From our study, a picture of the angulon emerges as an effective spin interacting with a magnetic field that is self-consistently generated by the molecule’s rotation. Moreover, we discuss rotational spectroscopy, which focuses on the response of rotating molecules to a laser perturbation in the linear response regime. Importantly, we take into account initial-state interactions that have been neglected in prior studies and reveal their impact on the excitation spectrum. To examine the angulon instability regime, we use a single-excitation ansatz and obtain results consistent with experiments, in which a broadening of spectral lines is observed while phonon wings remain highly suppressed due to initial-state interactions. Copyright © 2022, The Authors. All rights reserved.

关键词： Excited states

Log-periodic quantum magneto-oscillations and discrete-scale invariance in topological material HfTe5

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National science Review 2019年第5期6卷 914-920页

作者： Huichao Wang Yanzhao Liu Yongjie Liu Chuanying Xi Junfeng Wang Jun Liu Yong Wang Liang Li Shu Ping Lau Mingliang Tian Jiaqiang Yan David Mandrus Ji-Yan Dai Haiwen Liu Xincheng Xie Jian Wang International Center for Quantum Materials School of Physics Peking University Department of Applied Physics The Hong Kong Polytechnic University Wuhan National High Magnetic Field Center Huazhong University of Science and Technology High Magnetic Field Laboratory Chinese Academy of Sciences Center of Electron Microscopy State Key Laboratory of Silicon Materials School of Materials Science and Engineering Zhejiang University Materials Science and Technology Division Oak Ridge National Laboratory Department of Materials Science and Engineering University of Tennessee Center for Advanced Quantum Studies Department of PhysicsBeijing Normal University Collaborative Innovation Center of Quantum Matter CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing Academy of Quantum Information Sciences

Discrete-scale invariance（DSI） is a phenomenon featuring intriguing log-periodicity that can be rarely observed in quantum ***, we report the log-periodic quantum oscillations in the longitudinal magnetoresistivity(ρxx) and the Hall traces(ρyx) of Hf Te5 crystals, which reveal the DSI in the transport-coefficients *** oscillations in ρxxand ρyxshow the consistent log B-periodicity with a phase *** finding of the log B oscillations in the Hall resistance supports the physical mechanism as a general quantum effect originating from the resonant *** with theoretical simulations, we further clarify the origin of the log-periodic oscillations and the DSI in the topological *** work evidences the universality of the DSI in the Dirac materials and provides indispensable information for a full understanding of this novel phenomenon.

关键词： log-periodic oscillations discrete-scale invariance topological materials Dirac materials magnetoresistance Hall resistance

Topological modes in relativistic hydrodynamics

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Physical Review D 2021年第4期103卷 044044-044044页

作者： Yan Liu Ya-Wen Sun Center for Gravitational Physics Department of Space Science Beihang University Beijing 100191 China Key Laboratory of Space Environment Monitoring and Information Processing Ministry of Industry and Information Technology Beijing 100191 China School of physics and CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing 100049 China Kavli Institute for Theoretical Sciences University of Chinese Academy of Sciences Beijing 100049 China

We show that gapless modes in relativistic hydrodynamics could become topologically nontrivial by weakly breaking the conservation of energy momentum tensor in a specific way. This system has topological semimetal-like crossing nodes in the spectrum of hydrodynamic modes that require the protection of a special combination of translational and boost symmetries in two spatial directions. We confirm the nontrivial topology from the existence of an undetermined Berry phase. These energy momentum nonconservation terms could naturally be produced by an external gravitational field that comes from a reference frame change from the original inertial frame, i.e., by fictitious forces in a noninertial reference frame. This noninertial frame is the rest frame of an accelerating observer moving along a trajectory of a helix. This suggests that topologically trivial modes could become nontrivial by being observed in a special noninertial reference frame, and this fact could be verified in laboratories, in principle. Finally, we propose a holographic realization of this system.

关键词： Gauge-gravity dualities Topological phases of matter Hydrodynamics Relativistic hydrodynamics

Superconductivity and Fermi Surface Anisotropy in Transition Metal Dichalcogenide NbTe_2

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Chinese physics Letters 2019年第5期36卷 84-89页

作者： Xi Zhang Tianchuang Luo Xiyao Hu Jing Guo Gongchang Lin Yuehui Li Yanzhao Liu Xiaokang Li Jun Ge Ying Xing Zengwei Zhu Peng Gao Liling Sun Jian Wang International Center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871 Collaborative Innovation Center of Quantum Matter Beijing 100871 Institute of Physics and Beijing National Laboratory for Condensed Matter Physics Chinese Academy of SciencesBeijing 100190 Electron Microscopy Laboratory School of PhysicsPeking UniversityBeijing 100871 School of Physics Huazhong University of Science and TechnologyWuhan 430074 Wuhan National High Magnetic Field Center Huazhong University of Science and TechnologyWuhan 430074 Department of Materials Science and Engineering School of New Energy and MaterialsChina University of PetroleumBeijing 102249 Beijing Academy of Quantum Information Sciences Beijing 100193 University of Chinese Academy of Sciences Beijing 100190 Songshan Lake Materials Laboratory Dongguan 523808 CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100190

Transition metal dichalcogenides, featuring layered structures, have aroused enormous interest as a platform for novel physical phenomena and a wide range of potential applications. Among them, special interest has been placed upon WTe_2 and MoTe_2, which exhibit non-trivial topology both in single layer and bulk as well as pressure induced or enhanced superconductivity. We study another distorted IT material NbTe_2 through systematic electrical transport measurements. Intrinsic superconductivity with onset transition temperature(T_c^(onset)) up to 0.72 K is detected where the upper critical field(H_c) shows unconventional quasi-linear behavior,indicating spin-orbit coupling induced p-wave paring. Furthermore, a general model is proposed to fit the angledependent magnetoresistance, which reveals the Fermi surface anisotropy of NbTe_2. Finally, non-saturating linear magnetoresistance up to 50 T is observed and attributed to the quantum limit transport.

关键词： Superconductivity and Fermi Surface Anisotropy in Transition Metal Dichalcogenide NbTe2

Large-scale Evolution of Seconds-long Relativistic Jets from Black Hole-Neutron Star Mergers

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arXiv 2023年

作者： Gottlieb, Ore Issa, Danat Jacquemin-Ide, Jonatan Liska, Matthew Foucart, Francois Tchekhovskoy, Alexander Metzger, Brian D. Quataert, Eliot Perna, Rosalba Kasen, Daniel Duez, Matthew D. Kidder, Lawrence E. Pfeiffer, Harald P. Scheel, Mark A. Physics & Astronomy Northwestern University EvanstonIL60202 United States Institute for Theory and Computation Harvard University 60 Garden Street CambridgeMA02138 United States Department of Physics and Astronomy University of New Hampshire 9 Library Way DurhamNH03824 United States Department of Physics Columbia Astrophysics Laboratory Columbia University Pupin Hall New YorkNY10027 United States Center for Computational Astrophysics Flatiron Institute New YorkNY10010 United States Department of Astrophysical Sciences Princeton University PrincetonNJ08544 United States Department of Physics and Astronomy Stony Brook University Stony BrookNY11794-3800 United States Astronomy Department Theoretical Astrophysics Center University of California Berkeley BerkeleyCA94720 United States Physics Department University of California Berkeley BerkeleyCA94720 United States Nuclear Science Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Department of Physics & Astronomy Washington State University PullmanWA99164 United States Cornell Center for Astrophysics and Planetary Science Cornell University IthacaNY14853 United States PotsdamD-14467 Germany Tapir Walter Burke Institute for Theoretical Physics California Institute of Technology MC 350-17 PasadenaCA91125 United States

We present the first numerical simulations that track the evolution of a black hole-neutron star (BH-NS) merger from pre-merger to r 1011 cm. The disk that forms after a merger of mass ratio q = 2 ejects massive disk winds (3 - -5×10-2 Mo). We introduce various post-merger magnetic configurations and find that initial poloidal fields lead to jet launching shortly after the merger. The jet maintains a constant power due to the constancy of the large-scale BH magnetic flux until the disk becomes magnetically arrested (MAD), where the jet power falls off as Lj ∼ t-2. All jets inevitably exhibit either excessive luminosity due to rapid MAD activation when the accretion rate is high or excessive duration due to delayed MAD activation compared to typical short gamma-ray bursts (sGRBs). This provides a natural explanation for long sGRBs such as GRB 211211A but also raises a fundamental challenge to our understanding of jet formation in binary mergers. One possible implication is the necessity of higher binary mass ratios or moderate BH spins to launch typical sGRB jets. For post-merger disks with a toroidal magnetic field, dynamo processes delay jet launching such that the jets break out of the disk winds after several seconds. We show for the first time that sGRB jets with initial magnetization σ0 > 100 retain significant magnetization (σ 1) at r > 1010 cm, emphasizing the importance of magnetic processes in the prompt emission. The jet-wind interaction leads to a power-law angular energy distribution by inflating an energetic cocoon whose emission is studied in a companion paper. © 2023, CC BY.

关键词： Magnetization

Tomographic Alcock-Paczyński Test with Redshift-Space Correlation Function: Evidence for the Dark Energy Equation of State Parameter w > −1

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arXiv 2023年

作者： Dong, Fuyu Park, Changbom Hong, Sungwook E. Kim, Juhan Hwang, Ho Seong Park, Hyunbae Appleby, Stephen 85 Hoegiro Dongdaemun-gu Seoul02455 Korea Republic of Korea Astronomy and Space Science Institute 776 Daedeok-daero Yuseong-gu Daejeon34055 Korea Republic of University of Science and Technology Astronomy Campus 776 Daedeok-daero Yuseong-gu Daejeon34055 Korea Republic of Center for Advanced Computation Korea Institute for Advanced Study 85 Heogiro Dongdaemun-gu Seoul02455 Korea Republic of Astronomy Program Department of Physics and Astronomy Seoul National University 1 Gwanak-ro Gwanak-gu Seoul08826 Korea Republic of SNU Astronomy Research Center Seoul National University 1 Gwanak-ro Gwanak-gu Seoul08826 Korea Republic of Lawrence Berkeley National Laboratory CA94720-8139 United States Berkeley Center for Cosmological Physics UC Berkeley CA94720 United States Asia Pacific Center for Theoretical Physics Pohang37673 Korea Republic of Department of Physics POSTECH Pohang37673 Korea Republic of

The apparent shape of galaxy clustering depends on the adopted cosmology used to convert observed redshift to comoving distance, the r(z) relation, as it changes the line elements along and across the line of sight differently. The Alcock-Paczyński (AP) test exploits this property to constrain the expansion history of the universe. We present an extensive review of past studies on the AP test. We adopt an extended AP test method introduced by Park et al. (2019), which uses the full shape of redshift-space two-point correlation function (CF) as the standard shape, and apply it to the SDSS DR7, BOSS, and eBOSS LRG samples covering the redshift range up to z = 0.8. We calibrate the test against the nonlinear cosmology-dependent systematic evolution of the CF shape using the Multiverse simulations. We focus on examining whether or not the flat ΛCDM 'concordance' model is consistent with observation. We constrain the flat wCDM model to have w = −0.892+0.045-0.050 and Ωm = 0.282+0.024-0.023 from our AP test alone, which is significantly tighter than the constraints from the BAO or SNe Ia methods by a factor of 3-6. When the AP test result is combined with the recent BAO and SNe Ia results, we obtain w = −0.903+0.023-0.023 and Ωm = 0.285+0.014-0.009. This puts a strong tension with the flat ΛCDM model with w = −1 at 4.2σ level. Consistency with w = −1 is obtained only when the Planck CMB observation is combined. It remains to see if this tension between observations of galaxy distribution at low redshifts and CMB anisotropy at the decoupling epoch becomes greater in the future studies and leads us to a new paradigm of cosmology. © 2023, CC BY.

关键词： Equations of state