Article
Physics, Multidisciplinary
Ofer Aharony, Gabriel Cuomo, Zohar Komargodski, Mark Mezei, Avia Raviv-Moshe
Summary: We study the low-energy behavior of Wilson lines in conformal gauge theories and find that certain defect operators can become marginal, leading to interesting renormalization group flows and screening effects by charged fields. This screening phenomenon is universal in large enough representations of Wilson lines. We observe that fixed-point mergers are associated with the onset of the screening instability. By studying various applications, we show that the screening of Wilson lines can occur through dimensional transmutation or generation of large scales.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Hiroshi Shinaoka, Yuki Nagai
Summary: Quantum embedding theories can be used to describe correlated materials, but an effective impurity model of correlated orbitals embedded in an electron bath poses a challenge. This study proposes an efficient fitting algorithm for matrix-valued hybridization functions to address this issue, demonstrating its effectiveness in fitting hybridization functions and impurity models for high-Tc compounds.
Article
Physics, Condensed Matter
H. Sari, I. Sokmen
Summary: In this study, the simultaneous effects of anisotropy and internuclear distance on the self-polarization of the D+2 complex in quantum dots were investigated. Numerical calculations using the two-dimensional diagonalization method revealed that changes in internuclear distance and anisotropy parameter can regulate the effective confinement potential of the system. The variation in effective confinement potential plays a crucial role in the spatial elongation of the wave function and determines the observed behavior of the self-polarization effect.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Optics
Meritxell Cabrejo-Ponce, Andre Luiz Marques Muniz, Marcus Huber, Fabian Steinlechner
Summary: High-dimensional photonic entanglement has potential for error-protected quantum information processing. Encoding qudits in photon carrier frequency enables high-capacity quantum communication. This study demonstrates the harnessing of large frequency-entanglement in spontaneous parametric down-conversion processes and achieves efficient and nonlocal certification of discretized frequency entanglement. It opens possibilities for quantum communication and information science.
LASER & PHOTONICS REVIEWS
(2023)
Article
Mathematics
Anne Boutet de Monvel, Lech Zielinski
Summary: This paper investigates the large n asymptotics of the n-th eigenvalue for a class of unbounded self-adjoint operators defined by infinite Jacobi matrices with discrete spectrum. It obtains the first three terms of the asymptotics for the quantum Rabi model to determine the parameters of the model. This work is based on a previous paper and completes and improves upon its findings.
INTERNATIONAL MATHEMATICS RESEARCH NOTICES
(2021)
Article
Economics
Alain Guay, Florian Pelgrin
Summary: This paper proposes a joint methodology for identifying and inferring structural vector autoregressive models in the frequency domain. The authors utilize asymptotic least squares problems to establish identifying restrictions and propose a continuum asymptotic least squares estimator (C-ALS) to efficiently estimate impulse responses and confidence intervals. They also suggest using a formal test and a data-driven procedure to test the identifying restrictions and select the frequency band. Monte Carlo simulations and an application on the hours-productivity debate are provided.
JOURNAL OF ECONOMETRICS
(2023)
Article
Mathematics, Applied
Brahim Alouini, Hichem Hajaiej
Summary: This paper studies the dynamics of droplet formation in a dipolar Bose-Einstein condensate using an extended Gross-Pitaevskii equation. The stability of these droplets, which were discovered recently, needs to be mathematically explained and validated. Some research groups have made predictions about the properties of these droplets, and this paper aims to verify these predictions and address the challenges in simulating the dynamics of droplet formation.
ANALYSIS AND APPLICATIONS
(2023)
Article
Physics, Nuclear
Isaac Vidana
Summary: The study investigates the properties of a spin-down neutron impurity in a low-density free Fermi gas of spin-up neutrons, comparing the results with quantum Monte Carlo calculations and previous studies. It is found that the impurity's energy, effective mass, and quasiparticle residue exhibit slight variations within specific ranges, resembling those of an attractive Fermi polaron in the unitary limit. The research demonstrates compatibility with results derived from ultracold atoms, indicating similar properties under certain conditions.
Article
Statistics & Probability
Akio Fujiwara, Koichi Yamagata
Summary: We establish an asymptotic representation theorem for locally asymptotically normal quantum statistical models, allowing us to study the asymptotic efficiency of quantum estimators and providing a tight lower bound beyond the i.i.d. assumption. This complements the theory of quantum contiguity and establishes a solid foundation of weak quantum local asymptotic normality.
ANNALS OF STATISTICS
(2023)
Article
Optics
Wei-Hang Zhang, Ying-Hao Ye, Lei Zeng, Ming-Xin Dong, En-Ze LI, Jing-Yuan Peng, Yan LI, Dong-Sheng Ding, Bao-Sen Shi
Summary: In this experiment, the frequency down-conversion through the four-wave mixing process in a cold 85Rb atomic ensemble was investigated. The results showed that the frequency-conversion efficiency can reach up to 32% with an improvement in the optical depth. It was also found that the efficiency may exceed 32% when the signal-to-noise ratio of the detected telecom field is higher than 10 and the mean signal count is larger than 0.2. This work can be combined with quantum memories based on cold 85Rb ensemble to serve for long-distance quantum networks.
Article
Physics, Mathematical
Zeev Rudnick, Igor Wigman, Nadav Yesha
Summary: The paper examines the properties of Robin-Neumann gaps on various planar domains, providing a limiting mean value and specific upper and lower bounds in different scenarios. Further research is conducted on specific properties of different geometric structures.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Lin Li, Jin-Hua Sun, Wei Su, Zhen-Hua Wang, Dong-Hui Xu, Hong-Gang Luo, Wei-Qiang Chen
Summary: This study investigates the transport behavior of a hybrid superconductor-quantum-dot-superconductor junction, where the interplay between the Kondo effect and the proximity-induced p-wave pairing states is dominant. The Rashba spin-orbit coupling (RSOC) in the semiconductor leads to the creation of spin-triplet pairing components under the proximity-induced superconducting pairing interaction, leading to Zeeman-dependent splitting behaviors of the Yu-Shiba-Rusinov (YSR) state. The Zeeman field from the ferromagnet removes the spin degeneracy of quasiparticles excited in the triplet states, resulting in a phase transition when the ground state is a Kondo singlet.
Article
Mathematics, Applied
Rodrigo Clemente, Joao Marcos do O, Esteban da Silva, Evelina Shamarova
Summary: We study general problems in modeling electrostatic microelectromechanical systems devices and obtain results on the existence and regularity of a touchdown solution, as well as upper and lower bounds on the pull-in voltage. In a specific case, we find an exact asymptotic behavior of the touchdown solution near the origin when the associated differential equation involves a particular operator.
ADVANCES IN NONLINEAR ANALYSIS
(2023)
Article
Astronomy & Astrophysics
Nima Arkani-Hamed, Aaron Hillman, Sebastian Mizera
Summary: We introduce a class of polytopes that concisely capture the structure of UV and IR divergences of general Feynman integrals in Schwinger parameter space. These polytopes can be treated as worldline segments shrinking and expanding at different relative rates. We show that these polytopes have a remarkably simple dual description as cut out by linear inequalities defining the facets. The study provides a transparent geometric understanding and efficient computation method for leading UV and IR divergences.
Article
Mathematics, Applied
Wenji Zhang
Summary: The study investigates a chemotaxis-consumption system with generalized logistic source, constructing globally defined solutions and proving their convergence to spatially homogeneous equilibrium in the large time limit.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2021)
Article
Physics, Multidisciplinary
Han Xu, Xiang Li, Zhichao Zhou, Xin Wang, Lei Wang, Congjun Wu, Yu Wang
Summary: We used projector quantum Monte Carlo (QMC) simulation to investigate trion formation and quantum phase transition in an attractive SU(3) Hubbard model on a honeycomb lattice. Our simulations revealed a continuous quantum phase transition from semimetal to charge-density wave (CDW) as the attractive Hubbard interaction increased, with a critical coupling Uc/t = -1.52(2). Surprisingly, the critical exponents & nu; = 0.82(3) and & eta; = 0.58(4) determined by the QMC simulation did not agree with those predicted by the N = 3 chiral Ising universality class but rather matched the N = 1 chiral Ising universality class. Furthermore, we found that in the CDW phase, both on-site and off-site trions coexist, with the off-site trion forming a local bond state. This study not only provides insights into the formation of off-site trions in a two-dimensional Hubbard model but also questions the applicability of the GNY model to attractive SU(3) Dirac fermions.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Quantum Science & Technology
Guanjie He, Guo Xuan Chan, Xin Wang
Summary: Recent studies show that a multi-electron double-quantum-dot system may have advantages over the traditional case with only two confined electrons. The electron-phonon dephasing in a GaAs multi-electron double-quantum-dot system is investigated in both biased and unbiased cases. The results reveal that, in the biased case, the electron-phonon dephasing rate does not increase with the number of electrons, and a merit figure based on the exchange energy and dephasing rate actually increases with the number of electrons in the experimentally relevant range.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Materials Science, Multidisciplinary
Guo Xuan Chan, Peihao Huang, Xin Wang
Summary: Superexchange is a vital resource for long-range interaction between distant spins in largescale quantum computing. This study investigates a two-electron system in a linear triple-quantum-dot device, revealing the microscopic details of superexchange and its behavior. The results demonstrate nonmonotonic behavior of superexchange in the detuning regime and show that the relative detuning between the left and right dots can affect the magnitude of superexchange.
Article
Optics
Chengxian Zhang, Guo Xuan Chan, Xin Wang, Zheng-Yuan Xue
Summary: A key challenge in semiconductor quantum-dot charge qubits is achieving long-range qubit coupling and performing high-fidelity gates. This study presents a different type of charge qubit formed by an electron confined in a triple-quantum-dot system, enabling single and two-qubit gates in specific detuning sweet spots. The study also proposes a form of long-range dipolar coupling between the charge qubit and superconducting resonator, allowing for entangling gates in both dispersive and resonant regimes.
Article
Materials Science, Multidisciplinary
Guo Xuan Chan, Xin Wang
Summary: This study theoretically demonstrates the existence of sweet spots in singlet-triplet qubit systems and shows that, under realistic noise conditions, these sweet spots can achieve high-fidelity two-qubit operations.
Article
Optics
Guo Xuan Chan, Xin Wang
Summary: Studying the superexchange interaction in quantum dot systems, it has been found that increasing the number of mediating electrons and forming a four-electron triplet can enhance the superexchange.
Article
Materials Science, Multidisciplinary
Guo Xuan Chan, Xin Wang
Summary: This article investigates a singlet-triplet qubit defined by four-electron states in a double-quantum-dot system. The study demonstrates that the exchange energy as a function of detuning can be nonmonotonic in the four-electron singlet-triplet qubit, suggesting the existence of sweet spots. The authors also show that the tuning of the sweet spot and the corresponding exchange energy can be related to the variation of orbital splitting.
Article
Quantum Science & Technology
Chengxian Zhang, Tao Chen, Xin Wang, Zheng-Yuan Xue
Summary: A theoretical framework for implementing universal geometric quantum gates in semiconductor-based charge qubits confined in double quantum dots is provided to reduce the effects of charge noises. Through numerical simulation, it is shown that geometric gates outperform dynamical gates across a wide range of tunneling noise levels, particularly suitable to be used in conjunction with microwave driving. Introduction of a hybrid system allows for the construction of an entangling geometric gate with fidelity higher than that of the dynamical gate for experimentally relevant noise levels, suggesting that geometric quantum gates are powerful tools for high-fidelity manipulation of charge qubits.
ADVANCED QUANTUM TECHNOLOGIES
(2021)
Article
Materials Science, Multidisciplinary
Guo Xuan Chan, J. P. Kestner, Xin Wang
Summary: Theoretically, a range of nearly sweet spots appears in the coupled singlet-triplet qubit system when a strong enough external magnetic field is applied. Ramping to and from the judiciously chosen nearly sweet spot using sequences based on the shortcut to adiabaticity offers maximal gate fidelities under charge noise and phonon-induced decoherence, facilitating realization of high-fidelity two-qubit gates in singlet-triplet qubit systems.
Article
Optics
Han Xu, Lingna Wang, Haidong Yuan, Xin Wang
Summary: The study examines the generalizability of optimal control in quantum metrology, focusing on systematically updating control methods for different parameters to achieve efficient optimization in multiparameter quantum estimation.
Article
Optics
Xiao-Ming Zhang, Weicheng Kong, Muhammad Usman Farooq, Man-Hong Yung, Guoping Guo, Xin Wang
Summary: Our protocol uses detection-based quantum autoencoders to efficiently mitigate quantum errors without the need for extra qubits, offering near-optimal denoising power by removing errors detected outside of the latent subspace. This technique is particularly useful for near-term quantum devices with limited controllable qubits and a focus on noise reduction.
Article
Optics
Chengxian Zhang, Tao Chen, Sai Li, Xin Wang, Zheng-Yuan Xue
Article
Materials Science, Multidisciplinary
H. T. M. Nghiem, H. T. Dang, T. A. Costi
Article
Optics
Xiaopeng Li, Guanyu Zhu, Muxin Han, Xin Wang
Article
Optics
Xiao-Ming Zhang, Jianan Li, Xin Wang, Man-Hong Yung
