We propose a lumped element Josephson parametric amplifier with vacuum-gap-based capacitor.The capacitor is made of quasi-floating aluminum pad and on-chip ground.We take a fabrication process compatible with air-brid...We propose a lumped element Josephson parametric amplifier with vacuum-gap-based capacitor.The capacitor is made of quasi-floating aluminum pad and on-chip ground.We take a fabrication process compatible with air-bridge technology,which makes our design adaptable for future on-chip integrated quantum computing system.Further engineering the input impedance,we obtain a gain above 20 dB over 162-MHz bandwidth,along with a quasi quantum-limit noise performance.This work should facilitate the development of quantum information processing and integrated superconducting circuit design.展开更多
Noether’s theorem is one of the fundamental laws in physics,relating the symmetry of a physical system to its constant of motion and conservation law.On the other hand,there exist a variety of non-Hermitian parity-ti...Noether’s theorem is one of the fundamental laws in physics,relating the symmetry of a physical system to its constant of motion and conservation law.On the other hand,there exist a variety of non-Hermitian parity-time(PT)-symmetric systems,which exhibit novel quantum properties and have attracted increasing interest.In this work,we extend Noether’s theorem to a class of significant PT-symmetry systems for which the eigenvalues of the PT-symmetry Hamiltonian HPTchange from purely real numbers to purely imaginary numbers,and introduce a generalized expectation value of an operator based on biorthogonal quantum mechanics.We find that the generalized expectation value of a time-independent operator is a constant of motion when the operator presents a standard symmetry in the PT-symmetry unbroken regime,or a chiral symmetry in the PT-symmetry broken regime.In addition,we experimentally investigate the extended Noether’s theorem in PT-symmetry single-qubit and two-qubit systems using an optical setup.Our experiment demonstrates the existence of the constant of motion and reveals how this constant of motion can be used to judge whether the PT-symmetry of a system is broken.Furthermore,a novel phenomenon of masking quantum information is first observed in a PT-symmetry two-qubit system.This study not only contributes to full understanding of the relation between symmetry and conservation law in PT-symmetry physics,but also has potential applications in quantum information theory and quantum communication protocols.展开更多
The simplest spin-orbital model can host a nematic spin-orbital liquid state on the triangular lattice.We provide clear evidence that the ground state of the SU(4)Kugel-Khomskii model on the triangular lattice can be ...The simplest spin-orbital model can host a nematic spin-orbital liquid state on the triangular lattice.We provide clear evidence that the ground state of the SU(4)Kugel-Khomskii model on the triangular lattice can be well described by a‘‘single”Gutzwiller projected wave function with an emergent parton Fermi surface,despite it exhibits strong finite-size effect in quasi-one-dimensional cylinders.The finite-size effect can be resolved by the fact that the parton Fermi surface consists of open orbits in the reciprocal space.Thereby,a stripy liquid state is expected in the two-dimensional limit,which preserves the SU(4)symmetry while breaks the translational symmetry by doubling the unit cell along one of the lattice vector directions.It is indicative that these stripes are critical and the central charge is c=3,in agreement with the SU(4)1Wess-Zumino-Witten conformal field theory.All these results are consistent with the Lieb-Schultz-Mattis-Oshikawa-Hastings theorem.展开更多
It is increasingly important to understand the spatial dynamics of epidemics.While there are numerous mathematical models of epidemics,there is a scarcity of physical systems with sufficiently well-controlled paramete...It is increasingly important to understand the spatial dynamics of epidemics.While there are numerous mathematical models of epidemics,there is a scarcity of physical systems with sufficiently well-controlled parameters to allow quantitative model testing.It is also challenging to replicate the macro non-equilibrium effects of complex models in microscopic systems.In this work,we demonstrate experimentally a physics analog of epidemic spreading using optically-driven non-equilibrium phase transitions in strongly interacting Rydberg atoms.Using multiple laser beams we can impose any desired spatial structure.The observed spatially localized phase transitions simulate the outbreak of an infectious disease in multiple locations,and the splitting of the outbreak in subregions,as well as the dynamics towards“herd immunity”and“endemic state”in different regimes.The reported results indicate that Rydberg systems are versatile enough to model complex spatial-temporal dynamics.展开更多
基金the National Key Research and Development Program of China(Grant No.2016YFA0301200)the National Natural Science Foundation of China(Grant Nos.62074091,12004044,and U1930402)+2 种基金the Science Challenge Project(Grant No.TZ2018003)the Fund from the New Energy and Industrial Technology Development Organization(Grant No.JPNP16007)Japan Science and Technology Agency(Moonshot R&D,Grant No.JPMJMS2067 and CREST,Grant No.JPMJCR1676).
文摘We propose a lumped element Josephson parametric amplifier with vacuum-gap-based capacitor.The capacitor is made of quasi-floating aluminum pad and on-chip ground.We take a fabrication process compatible with air-bridge technology,which makes our design adaptable for future on-chip integrated quantum computing system.Further engineering the input impedance,we obtain a gain above 20 dB over 162-MHz bandwidth,along with a quasi quantum-limit noise performance.This work should facilitate the development of quantum information processing and integrated superconducting circuit design.
基金supported by the National Natural Science Foundation of China(Grant Nos.12264040,12204311,11804228,11865013,and U21A20436)the Jiangxi Natural Science Foundation(Grant Nos.20212BAB211018,20192ACBL20051)+8 种基金the Project of Jiangxi Province Higher Educational Science and Technology Program(Grant Nos.GJJ190891,and GJJ211735)the Key-Area Research and Development Program of Guangdong Province(Grant No.2018B03-0326001)supported in part by the Nippon Telegraph and Telephone(NTT)Corporation Researchthe Japan Science and Technology(JST)Agency[via the Quantum Leap Flagship Program(Q-LEAP)Moonshot R&D Grant Number JPMJMS2061]the Japan Society for the Promotion of Science(JSPS)[via the Grants-in-Aid for Scientific Research(KAKENHI)Grant No.JP20H00134]the Army Research Office(ARO)(Grant No.W911NF-18-1-0358)the Asian Office of Aerospace Research and Development(AOARD)(Grant No.FA2386-20-1-4069)the Foundational Questions Institute Fund(FQXi)(Grant No.FQXi-IAF19-06)。
文摘Noether’s theorem is one of the fundamental laws in physics,relating the symmetry of a physical system to its constant of motion and conservation law.On the other hand,there exist a variety of non-Hermitian parity-time(PT)-symmetric systems,which exhibit novel quantum properties and have attracted increasing interest.In this work,we extend Noether’s theorem to a class of significant PT-symmetry systems for which the eigenvalues of the PT-symmetry Hamiltonian HPTchange from purely real numbers to purely imaginary numbers,and introduce a generalized expectation value of an operator based on biorthogonal quantum mechanics.We find that the generalized expectation value of a time-independent operator is a constant of motion when the operator presents a standard symmetry in the PT-symmetry unbroken regime,or a chiral symmetry in the PT-symmetry broken regime.In addition,we experimentally investigate the extended Noether’s theorem in PT-symmetry single-qubit and two-qubit systems using an optical setup.Our experiment demonstrates the existence of the constant of motion and reveals how this constant of motion can be used to judge whether the PT-symmetry of a system is broken.Furthermore,a novel phenomenon of masking quantum information is first observed in a PT-symmetry two-qubit system.This study not only contributes to full understanding of the relation between symmetry and conservation law in PT-symmetry physics,but also has potential applications in quantum information theory and quantum communication protocols.
基金supported by the National Natural Science Foundation of China(12034004 and 11774306)the K.C.Wong Education Foundation(GJTD2020–01)+3 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDB28000000)funded by the European Research Council(ERC)under the European Unions Horizon 2020 Research and Innovation Program(771537)supported by the Deutsche Forschungsgemeinschaft through project A06 of SFB 1143(247310070)The numerical simulations in this work are based on the GraceQ project(www.gracequantum.org)。
文摘The simplest spin-orbital model can host a nematic spin-orbital liquid state on the triangular lattice.We provide clear evidence that the ground state of the SU(4)Kugel-Khomskii model on the triangular lattice can be well described by a‘‘single”Gutzwiller projected wave function with an emergent parton Fermi surface,despite it exhibits strong finite-size effect in quasi-one-dimensional cylinders.The finite-size effect can be resolved by the fact that the parton Fermi surface consists of open orbits in the reciprocal space.Thereby,a stripy liquid state is expected in the two-dimensional limit,which preserves the SU(4)symmetry while breaks the translational symmetry by doubling the unit cell along one of the lattice vector directions.It is indicative that these stripes are critical and the central charge is c=3,in agreement with the SU(4)1Wess-Zumino-Witten conformal field theory.All these results are consistent with the Lieb-Schultz-Mattis-Oshikawa-Hastings theorem.
基金funding from National Key R&D Program of China(2017YFA0304800)NSFC funding(Grant Nos.U20A20218,61525504,61722510,61435011)+7 种基金the Major Science and Technology Projects in Anhui Province(Grant No.202203a13010001)the Youth Innovation Promotion Association of CAS Grant No.2018490,EPSRC through grant agreements EP/M014398/1,EP/R002061/1,EP/L023024/1,EP/P012000/1,EP/R035482/1,EP/S015973/1,as well as,DSTL,and Durham UniversityThe European Union’s Horizon 2020 Research and Innovation Program under Grant No.845218(Marie Curie Fellowship to H.B.)F.N.is supported in part by:Nippon Telegraph and Telephone Corporation(NTT)Research,the Japan Science and Technology Agency(JST)[via the Quantum Leap Flagship Program(Q-LEAP),and the Moonshot R&D Grant Number JPMJMS2061]the Japan Society for the Promotion of Science(JSPS)[via the Grants-in-Aid for Scientific Research(KAKENHI)Grant No.JP20H00134]the Army Research Office(ARO)(Grant No.W911NF-18-1-0358)the Asian Office of Aerospace Research and Development(AOARD)(via Grant No.FA2386-20-1-4069)the Foundational Questions Institute Fund(FQXi)via Grant No.FQXi-IAF19-06.
文摘It is increasingly important to understand the spatial dynamics of epidemics.While there are numerous mathematical models of epidemics,there is a scarcity of physical systems with sufficiently well-controlled parameters to allow quantitative model testing.It is also challenging to replicate the macro non-equilibrium effects of complex models in microscopic systems.In this work,we demonstrate experimentally a physics analog of epidemic spreading using optically-driven non-equilibrium phase transitions in strongly interacting Rydberg atoms.Using multiple laser beams we can impose any desired spatial structure.The observed spatially localized phase transitions simulate the outbreak of an infectious disease in multiple locations,and the splitting of the outbreak in subregions,as well as the dynamics towards“herd immunity”and“endemic state”in different regimes.The reported results indicate that Rydberg systems are versatile enough to model complex spatial-temporal dynamics.
