Article
Physics, Multidisciplinary
Shah Saad Alam, Timothy Skaras, Li Yang, Han Pu
Summary: Dynamical fermionization phenomenon in Tonks-Girardeau gases shows that the momentum density profile approaches that of an ideal Fermi gas after being released from harmonic confinement. By extending the study to a one-dimensional spinor gas of arbitrary spin in a strongly interacting regime, it is analytically proven that the total momentum distribution resembles that of a spinless ideal Fermi gas and each spin component maintains the shape of the initial real space density profile.
PHYSICAL REVIEW LETTERS
(2021)
Article
Optics
Kuan-Yu Li, Yicheng Zhang, Kangning Yang, Kuan-Yu Lin, Sarang Gopalakrishnan, Marcos Rigol, Benjamin L. Lev
Summary: We investigate the impact of tunable integrability-breaking dipole-dipole interactions on the equilibrium states of 1D Bose gases of dysprosium at low temperatures. Our experimental results show that in the strongly correlated Tonks-Girardeau regime, rapidity and momentum distributions are unaffected by the dipolar interactions. However, significant changes occur when the strength of the contact interactions is decreased. We propose a model that captures the main experimental observations by considering the system as an array of 1D gases with only contact interactions, dressed by the contribution of the short-range part of the dipolar interactions.
Article
Materials Science, Multidisciplinary
Patrycja Lydzba, Janez Bonca
Summary: The study investigates the unitary time evolution of a symmetry-broken state in a finite system of interacting hard-core bosons, which can be mapped onto the XXZ Heisenberg chain. A spatially homogeneous and time-dependent vector potential is introduced to mimic a short laser pulse, allowing control over the onset of charge density wave order. Nonthermal long-lived states with nonzero charge density wave order, translated by one lattice site, are found to have lifetimes significantly longer than typical times given by the system parameters, although they are suppressed by integrability-breaking perturbations. The existence of these long-lived nonthermal states in the thermodynamic limit is speculated based on the findings.
Article
Materials Science, Multidisciplinary
Ritu Nehra, Dibyendu Roy
Summary: The multipartite non-Hermitian Su-Schrieffer-Heeger model is investigated as a representative example of one-dimensional systems with multiple sublattice sites, revealing intriguing insulating and metallic phases with no Hermitian counterparts. The topology of these composite loops, characterized by multiple complex-energy bands encircling exceptional points on the parametric space, resembles well-known topological objects and can be quantified by a nonadiabatic cyclic geometric phase involving only the participating bands.
Article
Optics
Manuele Tettamanti, Alberto Parola
Summary: The study investigates the existence and stability of solitonic states in one-dimensional repulsive Bose-Einstein condensates by considering the limit of infinite repulsion. A class of stationary, shape-invariant states propagating at constant velocity are found and compared to the known solution of the Gross-Pitaevskii equation. The results show that typical nonlinear features can be recovered in a purely linear theory when the full many-body physics is correctly taken into account.
Article
Physics, Condensed Matter
Hao Fu, Mingqiu Luo, Peiqing Tong
Summary: The Lieb-Robinson bound (LRB) is numerically studied in one-dimensional noninteracting many-electron systems with disordered and quasiperiodic on-site potentials. For the short-range hopping system, a logarithmic light cone is found in the presence of a disordered on-site potential, which decreases with increasing disorder strength. In the long time limit, the bound does not change with time. For the generalized Fibonacci quasiperiodic system, a power-law light cone is observed, with the exponent decreasing as the strength of the potential increases. It is also found that the exponent is larger for the first class of GFQ system compared to the second class with the same potential. Lastly, the effects of long-range hopping on the LRB are discussed.
PHYSICA B-CONDENSED MATTER
(2022)
Article
Optics
J. Talukdar, D. Blume
Summary: We investigate an array of noninteracting qubits or emitters coupled to a one-dimensional cavity array with tunneling energy and nonlinearity. By eliminating the photonic degrees of freedom, we obtain a one-dimensional spin Hamiltonian with effective interactions, featuring constrained single-qubit hopping and pair hopping interactions. We identify parameter combinations for the system to support droplet-like bound states.
Article
Multidisciplinary Sciences
Stefan Birnkammer, Alvise Bastianello, Michael Knap
Summary: This study investigates the thermalization dynamics after a quantum quench in confined systems and finds that it exhibits multiple stages. Taking the confined Ising spin chain as an example, bound states resembling mesons are formed. The system first reaches a prethermal state related to the number of conserved mesons, and then achieves true thermal equilibrium at much later times.
NATURE COMMUNICATIONS
(2022)
Article
Optics
Francois Riggio, Yannis Brun, Dragi Karevski, Alexandre Faribault
Summary: The local-density approximation (LDA) is a commonly used technique in modeling quantum gases, but it has large approximation errors in the ground state of one-dimensional Bose gases. In this study, we propose a method to correct LDA by treating the local density as a functional of the trapping potential and applying a gradient expansion. The correction coefficients are determined through perturbative calculations and can be evaluated numerically or analytically. The corrected LDA shows significant improvement compared to the zeroth-order LDA.
Article
Materials Science, Multidisciplinary
Rebecca Kraus, Titas Chanda, Jakub Zakrzewski, Giovanna Morigi
Summary: In this article, a theoretical analysis of the phase diagram of a quantum gas of bosons interacting via repulsive dipolar interactions is conducted. Numerical techniques are used to evaluate the phase diagram for unit density, revealing a significant impact of correlated tunneling on the parameter range of the topological insulator phase.
Article
Nanoscience & Nanotechnology
Weronika Glowadzka, Michal Wasiak, Tomasz Czyszanowski
Summary: This study explores the possibility of realizing bound states in the continuum (BICs) in systems with broken symmetry, demonstrating that high-quality factor BICs can be achieved in gratings with broken up-down mirror symmetry. The research also shows potential for creating micro- and nanooptical cavities in standard all-semiconductor technology with Q-factors above 10^4.
Article
Mechanics
Marco Baldovin, Stefano Iubini
Summary: The study focuses on nonequilibrium steady states in a class of one-dimensional diffusive systems capable of reaching negative absolute temperatures. Various systems, including paramagnetic spin systems, Hamiltonian rotator chains, and one-dimensional discrete linear Schrodinger equations, were considered. The research demonstrates that a phenomenological description using a Fourier law can effectively explain unusual transport regimes where temperature profiles exhibit negative-temperature regions. This negative-temperature Fourier transport phenomenon is observed in both deterministic and stochastic dynamics, and can also be extended to coupled transport scenarios with multiple thermodynamic currents.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2021)
Article
Chemistry, Physical
Camille Lagoin, Stephan Suffit, Kirk Baldwin, Loren Pfeiffer, Francois Dubin
Summary: In an artificial square lattice, we manipulate a Bose-Fermi mixture by confining neutral and charged dipolar excitons. At specific lattice filling, strong inter- and intraspecies interactions lead to insulating phases and the realization of dual Bose-Fermi density waves.
Article
Mathematics, Applied
Victor Barrera-Figueroa
Summary: This paper investigates the characteristic functions of one-dimensional Schrödinger operators, discussing general properties and numerical treatment methods.
APPLIED MATHEMATICS AND COMPUTATION
(2022)
Article
Chemistry, Physical
Yufeng Zhang, Xiangzhuo Xing, Yan Meng, Xiaolei Yi, Jun Gouchi, Dilip Bhoi, Jiajia Feng, Yaojun Fan, Wei Zhou, Nan Zhou, Yoshiya Uwatoko, Zhixiang Shi
Summary: Superconductivity is discovered in quasi-one-dimensional SrBi2Se4 single crystals grown by the self-flux method, showing metallic behavior in the normal state and a superconducting transition at low temperatures. Both magnetization and specific heat measurements confirm the bulk nature of superconductivity, with an upper critical field significantly larger than the Pauli limit. The field dependence of resistivity at certain temperatures exhibits an anomalously hump-like feature, indicating reentrant vortex pinning induced by increasing magnetic fields.
CHEMISTRY OF MATERIALS
(2021)
Article
Physics, Multidisciplinary
Kasper Poulsen, Nikolaj T. Zinner
Summary: Giant magnetoresistance has been observed in a spin chain composed of weakly interacting layers of strongly coupled spins, even in systems as small as four spins. The effect is driven by a mismatch in the energy spectrum leading to spin excitations being reflected at layer boundaries, which can be controlled by external magnetic fields to achieve giant magnetoresistance. A simple rule based on the energy levels of the strongly coupled spins can predict the behavior of spin transport under the influence of a magnetic field.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Oleksandr Marchukov, Artem G. Volosniev
Summary: In this study, the Gross-Pitaevskii equation is used to investigate acoustic emission generated in a uniform Bose gas by a static impurity, exploring the shape of the sound-wave packet and its potential in extracting impurity properties. The results are general for all one-dimensional systems and can be applied to non-atomic systems, such as analyzing light propagation in nonlinear optical media.
Article
Physics, Applied
E. Bahnsen, S. E. Rasmussen, N. J. S. Loft, N. T. Zinner
Summary: As the application of quantum technology approaches, leveraging current quantum resources becomes crucial. Utilizing the diamond gate instead of standard gates has shown to be more efficient in compiling quantum algorithms. These gates can be decomposed into standard gates and have a wide range of applications in quantum machine learning.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Multidisciplinary
Kasper Poulsen, Alan C. Santos, Nikolaj T. Zinner
Summary: We propose a quantum Wheatstone bridge as a fully quantum analog to the classical version, which exploits quantum effects to enhance sensitivity to an unknown coupling. This can be used in fields such as sensing and metrology.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Stig Elkjaer Rasmussen, Nikolaj Thomas Zinner
Summary: This study focuses on the effect of parameterized two-qubit gates in the variational quantum eigensolver. By simulating the algorithm using fixed and parameterized two-qubit gates, it is shown that the parameterized versions outperform the fixed versions in terms of best energy and reducing outliers.
ANNALEN DER PHYSIK
(2022)
Article
Quantum Science & Technology
Frederik Kofoed Marqversen, Nikolaj Thomas Zinner
Summary: We discuss the procedure for obtaining measurement-based implementations of quantum algorithms given by quantum circuit diagrams and how to reduce the required resources needed for a given measurement-based computation. This forms the foundation for quantum computing on photonic systems in the near term. To demonstrate that these ideas are well grounded we present three different problems which are solved by employing a measurement-based implementation of the variational quantum eigensolver algorithm (MBVQE). We show that by utilising native measurement-based gates rather than standard gates, such as the standard controlled not gate (CNOT), measurement-based quantum computations may be obtained that are both shallow and have simple connectivity while simultaneously exhibiting a large expressibility. We conclude that MBVQE has promising prospects for resource states that are not far from what is already available today.
QUANTUM SCIENCE AND TECHNOLOGY
(2023)
Article
Optics
Lasse Bjorn Kristensen, Morten Kjaergaard, Christian Kraglund Andersen, Nikolaj Thomas Zinner
Summary: This research presents a hybrid approach combining autonomous correction and traditional measurement-based quantum error correction to correct the dominant phase and decay errors in superconducting qubit architectures. Numerical simulations demonstrate that this scheme can significantly increase the storage time by five to ten times and requires only six qubits for encoding and two ancillary qubits for autonomous correction, leading to a substantial reduction in qubit overhead compared to typical measurement-based error-correction schemes. Furthermore, this scheme can be implemented in a wide range of architectures as it relies on standard interactions and qubit driving available in most major quantum computing platforms.
Article
Chemistry, Multidisciplinary
Marco Majland, Rasmus Berg Jensen, Mads Greisen Hojlund, Nikolaj Thomas Zinner, Ove Christiansen
Summary: The excessive measurement overheads in estimating physical quantities hinder the demonstration of practical quantum advantages for near-term devices. However, the reduction in resource requirements for computing anharmonic, vibrational states remains unexplored compared to its electronic counterpart. Through the manipulation of vibrational systems, such as employing coordinate transformations, we can significantly reduce the number of measurements needed to estimate anharmonic, vibrational states.
Article
Materials Science, Multidisciplinary
A. Alnor, T. Baekkegaard, N. T. Zinner
Summary: Different topological phases of quantum systems have been a focus of research in recent decades. This study goes beyond typical spin-1/2 systems and explores the realization of higher Chern numbers and the emergence of different topological phases using spin-1 systems. The results show that rich topological phase diagrams can be achieved through numerical and analytical methods, and the realistic implementation of spin-1 systems in superconducting circuits holds promise for experimental verification of these theoretical predictions.
Article
Optics
S. E. Rasmussen, N. T. Zinner
Summary: In this paper, the entangling quantum generative adversarial network (EQ-GAN) is investigated for multiqubit learning. It is shown that EQ-GAN can learn circuits more efficiently than SWAP test and generate excellent overlap matrix elements for learning VQE states of small molecules. However, the lack of phase estimation prevents it from directly estimating energy. Additionally, EQ-GAN demonstrates its potential in learning random states.
Article
Physics, Fluids & Plasmas
Kasper Poulsen, Nikolaj T. Zinner
Summary: Heat and noise control are crucial for the development of quantum technologies. Heat rectifiers, which allow for one-way heat transport, are powerful tools for this purpose. We propose a rectifier based on the unidirectionality of a low temperature bath, which can block heat transport in one configuration but allow it in the other.
Article
Optics
Kasper Poulsen, Alan C. Santos, Lasse B. Kristensen, Nikolaj T. Zinner
Summary: This study introduces a class of quantum rectifiers that can improve performance by utilizing quantum entanglement. By coupling two small spin chains through a double-slit interface, rectification can be significantly enhanced, even in small systems, and the effect can withstand noisy environments.
Article
Physics, Fluids & Plasmas
Kasper Poulsen, Marco Majland, Seth Lloyd, Morten Kjaergaard, Nikolaj T. Zinner
Summary: Maxwell's demon is a quintessential example of information control necessary for designing quantum devices. Our study demonstrates that non-Markovian effects can be exploited to optimize the information transfer rate in quantum Maxwell demons.
Article
Physics, Multidisciplinary
Mikhail Maslov, Mikhail Lemeshko, Artem G. Volosniev
Summary: We study the impact of an impurity with a resonance level on a surrounding Fermi gas. Our findings show that the impurity causes changes in its self-energy and the density of the gas, leading to a model-independent deformation of the Fermi gas density. Additionally, the study investigates the time evolution of the density in quench dynamics and the behavior of the system at finite temperatures.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Quantum Science & Technology
S. E. Rasmussen, K. S. Christensen, S. P. Pedersen, L. B. Kristensen, T. Baekkegaard, N. J. S. Loft, N. T. Zinner
Summary: This tutorial provides an introductory treatment of circuit analysis of superconducting qubits, including couplings, microwave driving, and noise considerations. It is intended for new researchers with limited experience and covers basic methods, examples, and common circuit designs for quantum-information applications.
