We studied the dynamic correlations of non-integrable systems with quantum many-body scar(QMBS)states generated by a ladder operator.The ladder operator's spectral function has an exact δ-function peak induced by...We studied the dynamic correlations of non-integrable systems with quantum many-body scar(QMBS)states generated by a ladder operator.The ladder operator's spectral function has an exact δ-function peak induced by the QMBS states.As a concrete example,we show that in the one-dimensional(1D)spin-1 Affleck-Kennedy-Lieb-Tasaki model,the spectral function of two-magnon excitations exhibits a characteristic bowtie shape composed of aδ-function resonance peak at momentum k=π and a continuum spectrum elsewhere.The two-magnon excitations can be observed via resonant inelastic X-ray scattering spectroscopy on quasi-1D nickelates and other spin-1 antiferromagnetic materials.Therefore,the findings of this study pave the way for detecting(approximate)QMBS states in realistic materials.展开更多
We present the first numerical solution that corresponds to a pair of Cho–Maison monopoles and antimonopoles(MAPs) in the SU(2) × U(1) Weinberg–Salam(WS) theory.The monopoles are finitely separated,while each p...We present the first numerical solution that corresponds to a pair of Cho–Maison monopoles and antimonopoles(MAPs) in the SU(2) × U(1) Weinberg–Salam(WS) theory.The monopoles are finitely separated,while each pole carries a magnetic charge ±4π/e.The positive pole is situated in the upper hemisphere,whereas the negative pole is in the lower hemisphere.The Cho–Maison MAP is investigated for a range of Weinberg angles,0.4675≤ tan θ_(W)≤10,and Higgs self-coupling,0 ≤ β ≤ 1.7704.The magnetic dipole moment(μm) and pole separation(d_(z)) of the numerical solutions are calculated and analyzed.The total energy of the system,however,is infinite due to point singularities at the locations of monopoles.展开更多
We revisit the construction of the N=1 supersymmetric trinification models with gauge group U(3)_(C)×U(3)_(L)×U(3)_(R) in TypeⅡA string theory on T^(6)(Z_(2)×Z_(2))orientifold with intersecting D6-bran...We revisit the construction of the N=1 supersymmetric trinification models with gauge group U(3)_(C)×U(3)_(L)×U(3)_(R) in TypeⅡA string theory on T^(6)(Z_(2)×Z_(2))orientifold with intersecting D6-branes.The non-trivial K-theory conditions and tadpole cancellation conditions severely restrict the number of allowed models even for the case of rectangular two-tori.Using a supervised search algorithm,we find a few four-family models where the highest wrapping number is 2.For these models,we present the complete particle spectra and the gauge coupling relations at the string-scale.展开更多
Scalar-tensor theories of gravity are considered to be competitors to Einstein's theory of general relativity for the description of classical gravity,as they are used to build feasible models for cosmic inflation...Scalar-tensor theories of gravity are considered to be competitors to Einstein's theory of general relativity for the description of classical gravity,as they are used to build feasible models for cosmic inflation.These theories can be formulated both in the Jordan and Einstein frame,which are related by a Weyl transformation with a field transformation,known together as a frame transformation.These theories formulated in the above two frames are often considered to be equivalent from the point of view of classical theory.However,this is no longer true from the quantum field theoretical perspective.In the present article,we show that the Ward identities derived in the above two frames are not connected through the frame transformation.This shows that the quantum field theories formulated in these two frames are not equivalent to each other.Moreover,this inequivalence is also shown by comparing the effective actions derived in these two frames.展开更多
By using the numerical renormalization group(NRG)method,we construct a large dataset with about one million spectral functions of the Anderson quantum impurity model.The dataset contains the density of states(DOS)of t...By using the numerical renormalization group(NRG)method,we construct a large dataset with about one million spectral functions of the Anderson quantum impurity model.The dataset contains the density of states(DOS)of the host material,the strength of Coulomb interaction between on-site electrons(U),and the hybridization between the host material and the impurity site(Γ).The continued DOS and spectral functions are stored with Chebyshev coefficients and wavelet functions,respectively.From this dataset,we build seven different machine learning networks to predict the spectral function from the input data,DOS,U,andΓ.Three different evaluation indexes,mean absolute error(MAE),relative error(RE)and root mean square error(RMSE),are used to analyze the prediction abilities of different network models.Detailed analysis shows that,for the two kinds of widely used recurrent neural networks(RNNs),gate recurrent unit(GRU)has better performance than the long short term memory(LSTM)network.A combination of bidirectional GRU(BiGRU)and GRU has the best performance among GRU,BiGRU,LSTM,and BiLSTM.The MAE peak of BiGRU+GRU reaches 0.00037.We have also tested a one-dimensional convolutional neural network(1DCNN)with 20 hidden layers and a residual neural network(ResNet),we find that the 1DCNN has almost the same performance of the BiGRU+GRU network for the original dataset,while the robustness testing seems to be a little weak than BiGRU+GRU when we test all these models on two other independent datasets.The ResNet has the worst performance among all the seven network models.The datasets presented in this paper,including the large data set of the spectral function of Anderson quantum impurity model,are openly available at https://doi.org/10.57760/sciencedb.j00113.00192.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12174387)the Chinese Academy of Sciences(Grant Nos.YSBR-057 and JZHKYPT-2021-08)the Innovative Program for Quantum Science and Technology(Grant No.2021ZD0302600)。
文摘We studied the dynamic correlations of non-integrable systems with quantum many-body scar(QMBS)states generated by a ladder operator.The ladder operator's spectral function has an exact δ-function peak induced by the QMBS states.As a concrete example,we show that in the one-dimensional(1D)spin-1 Affleck-Kennedy-Lieb-Tasaki model,the spectral function of two-magnon excitations exhibits a characteristic bowtie shape composed of aδ-function resonance peak at momentum k=π and a continuum spectrum elsewhere.The two-magnon excitations can be observed via resonant inelastic X-ray scattering spectroscopy on quasi-1D nickelates and other spin-1 antiferromagnetic materials.Therefore,the findings of this study pave the way for detecting(approximate)QMBS states in realistic materials.
文摘We present the first numerical solution that corresponds to a pair of Cho–Maison monopoles and antimonopoles(MAPs) in the SU(2) × U(1) Weinberg–Salam(WS) theory.The monopoles are finitely separated,while each pole carries a magnetic charge ±4π/e.The positive pole is situated in the upper hemisphere,whereas the negative pole is in the lower hemisphere.The Cho–Maison MAP is investigated for a range of Weinberg angles,0.4675≤ tan θ_(W)≤10,and Higgs self-coupling,0 ≤ β ≤ 1.7704.The magnetic dipole moment(μm) and pole separation(d_(z)) of the numerical solutions are calculated and analyzed.The total energy of the system,however,is infinite due to point singularities at the locations of monopoles.
文摘We revisit the construction of the N=1 supersymmetric trinification models with gauge group U(3)_(C)×U(3)_(L)×U(3)_(R) in TypeⅡA string theory on T^(6)(Z_(2)×Z_(2))orientifold with intersecting D6-branes.The non-trivial K-theory conditions and tadpole cancellation conditions severely restrict the number of allowed models even for the case of rectangular two-tori.Using a supervised search algorithm,we find a few four-family models where the highest wrapping number is 2.For these models,we present the complete particle spectra and the gauge coupling relations at the string-scale.
文摘Scalar-tensor theories of gravity are considered to be competitors to Einstein's theory of general relativity for the description of classical gravity,as they are used to build feasible models for cosmic inflation.These theories can be formulated both in the Jordan and Einstein frame,which are related by a Weyl transformation with a field transformation,known together as a frame transformation.These theories formulated in the above two frames are often considered to be equivalent from the point of view of classical theory.However,this is no longer true from the quantum field theoretical perspective.In the present article,we show that the Ward identities derived in the above two frames are not connected through the frame transformation.This shows that the quantum field theories formulated in these two frames are not equivalent to each other.Moreover,this inequivalence is also shown by comparing the effective actions derived in these two frames.
基金Project supported by the National Natural Science Foundation of China(Grant No.12174101)the Fundamental Research Funds for the Central Universities(Grant No.2022MS051)。
文摘By using the numerical renormalization group(NRG)method,we construct a large dataset with about one million spectral functions of the Anderson quantum impurity model.The dataset contains the density of states(DOS)of the host material,the strength of Coulomb interaction between on-site electrons(U),and the hybridization between the host material and the impurity site(Γ).The continued DOS and spectral functions are stored with Chebyshev coefficients and wavelet functions,respectively.From this dataset,we build seven different machine learning networks to predict the spectral function from the input data,DOS,U,andΓ.Three different evaluation indexes,mean absolute error(MAE),relative error(RE)and root mean square error(RMSE),are used to analyze the prediction abilities of different network models.Detailed analysis shows that,for the two kinds of widely used recurrent neural networks(RNNs),gate recurrent unit(GRU)has better performance than the long short term memory(LSTM)network.A combination of bidirectional GRU(BiGRU)and GRU has the best performance among GRU,BiGRU,LSTM,and BiLSTM.The MAE peak of BiGRU+GRU reaches 0.00037.We have also tested a one-dimensional convolutional neural network(1DCNN)with 20 hidden layers and a residual neural network(ResNet),we find that the 1DCNN has almost the same performance of the BiGRU+GRU network for the original dataset,while the robustness testing seems to be a little weak than BiGRU+GRU when we test all these models on two other independent datasets.The ResNet has the worst performance among all the seven network models.The datasets presented in this paper,including the large data set of the spectral function of Anderson quantum impurity model,are openly available at https://doi.org/10.57760/sciencedb.j00113.00192.
