Article
Optics
Damian Wlodzynski
Summary: A method for numerically exact calculation is proposed in this article for a mixture with a single impurity and several majority fermions in a harmonic potential. The method separates one degree of freedom through a tailored canonical transformation and performs exact diagonalization on the simplified Hamiltonian. This method is particularly effective for heavy impurities.
Article
Optics
Manuel Valiente
Summary: The study developed a general theory of local unitary transformations between one-dimensional quantum systems of bosons and fermions with various low-energy interactions. These transformations generate families of duality relations and models linking the strong- and weak-coupling limits of the respective dual theories.
Article
Multidisciplinary Sciences
Rodolfo Jose Bueno Rogerio, Luca Fabbri
Summary: In this paper, a new class of spin-half mass-dimension one fermions is obtained using the machinery introduced in Ahluwalia (Ahluwalia 2020. Phys. Eng. Sci. 476, 20200249. (doi:10.1098/rspa.2020.0249) and EPL 131, 41001. (doi:10.1209/0295-5075/131/41001)). These spinors, after a suitable dual structure examination, can serve as expansion coefficients for a local field.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2022)
Article
Optics
Jeff Maki, Tilman Enss
Summary: The scattering properties of spin-polarized Fermi gases are mainly influenced by p-wave interactions, which differ from s-wave interactions due to their angular dependence and the necessity of an effective range. This article investigates the dependence of shear viscosity and thermal conductivity on the effective range and scattering volume in both weakly and strongly interacting limits for a three-dimensional spin-polarized Fermi gas in the normal phase. The study reveals that, while the shear viscosity and thermal conductivity depend on the effective range near resonance, the Prandtl number, which represents the ratio of momentum to thermal diffusivity, does not exhibit an explicit interaction dependence at resonance or for weak interactions in the low-energy range. Unlike s-wave systems, p-wave scattering shows an additional resonance at weak attraction, resulting in a significant dip in shear viscosity at specific temperatures.
Article
Optics
Gianni Aupetit-Diallo, Silvia Musolino, Mathias Albert, Patrizia Vignolo
Summary: We investigate the equilibrium momentum distribution of strongly interacting one-dimensional mixtures of particles at zero temperature confined in a box potential. We find that the magnitude of the tail of the momentum distribution, characterized by 1/k4, is influenced not only by short-distance correlations but also by the presence of rigid walls. This additional contribution, which includes a k-independent term and an oscillating part, breaks the Tan relation and surprisingly encodes information on long-range spin correlations.
Article
Physics, Particles & Fields
Cheng-Yang Lee
Summary: The research focuses on a non-local and non-covariant theory of fermionic fields associated with flag-pole spinors, utilizing a matrix transformation and varying a specific parameter z. It is found that fermionic fields are physically equivalent at |z| not equal to 1 and |z| = 1, but exhibit additional fermionic degeneracy for multiple values of z. The study explores fermionic self-interaction and local U(1) interaction, revealing non-local contributions and non-commutative interaction density at space-like separation.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Materials Science, Multidisciplinary
L. Crippa, A. Amaricci, S. Adler, G. Sangiovanni, M. Capone
Summary: The impact of Coulomb interaction on the electronic properties of a quantum spin Hall insulator has been studied using quantum cluster methods, with a focus on disentangling local from nonlocal effects. Different regimes have been identified based on the value of the bare mass term, with significant differences in self-energy contributions. The study shows that for small mass, nonlocal correlations become important and eventually dominate over local ones near the zero-mass semimetallic line, while for intermediate and large mass, local correlation effects outweigh nonlocal corrections, leading to a first-order topological phase transition.
Article
Multidisciplinary Sciences
Przemyslaw Koscik, Arkadiusz Kuros, Adam Pieprzycki, Tomasz Sowinski
Summary: This study presents a highly accurate variational scheme for describing the ground state of a system of a few ultra-cold bosons confined in one-dimensional traps of arbitrary shapes. The proposed method shows efficiency across a range of intermediate interactions under different external potentials. The results highlight that mutual correlations forced by interactions in generic non-parabolic potentials cannot be captured by distance-dependent functions.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Lucia Vigliotti, Fabio Cavaliere, Matteo Carrega, Niccolo Traverso Ziani
Summary: In topological superconductors, both Majorana bound states and Tamm bound states can coexist, with Tamm states remaining partially localized even in the absence of an energy gap. However, the Majorana polarization shows a clear transition between the two regimes.
Article
Physics, Multidisciplinary
Przemyslaw Koscik, Tomasz Sowinski
Summary: We investigate the ground state of polarized fermions interacting through zero-range p-wave forces in one dimension. We prove that in the limit of infinite attraction, the spectral properties of any-order reduced density matrix describing arbitrary subsystems are independent of the shape of an external potential. Furthermore, we show that the purity of these matrices, which quantifies the amount of quantum correlations, can be analytically obtained for any number of particles without diagonalization. This observation serves as a rigorous benchmark for models and methods studying strongly interacting p-wave fermions.
PHYSICAL REVIEW LETTERS
(2023)
Review
Physics, Multidisciplinary
Dharam Vir Ahluwalia, Julio M. Hoff da Silva, Cheng-Yang Lee, Yu-Xiao Liu, Saulo H. Pereira, Masoumeh Moazzen Sorkhi
Summary: This article introduces the spin and spinor and their transformation rules, and introduces the ELKO spinors and two quantum fields, discussing their mass dimension and locality. The existence of spin half bosonic and fermionic dark matter candidates is proposed, and interaction theories and Newtonian gravitational interaction calculations are given. Finally, the thermodynamic properties of the mass dimension one fermionic field in the dark matter halo and higher-dimensional ELKO in braneworld scenarios are studied.
PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS
(2022)
Article
Astronomy & Astrophysics
Diego Alvarez-Ortega, Gonzalo J. Olmo, Diego Rubiera-Garcia, Diego Saez-Chillon Gomez
Summary: Interacting dark-energy-dark-matter models have been analyzed in an attempt to find traces of new physics. The study shows that by introducing an appropriate coupling, dark-matter observers can see a non beginning, non ending universe, and this type of coupling can fit observational data.
Article
Mathematics, Interdisciplinary Applications
Wang Jun, Cao Lei, Wang Bin, Gong Hongtao, Tang Wei
Summary: One-dimensional continuous functions are fundamental in studying complex functions. The properties of these functions, such as dimensionality, continuity, and boundedness, have been discussed from various perspectives. This article systematically sorts out existing conclusions based on bounded variation, unbounded variation, and Hodler continuity. Additionally, it explores the innovative use of unbounded variation points in analyzing continuous functions and constructing functions with unbounded variation. The potential applications of fractals and fractal dimension in reinforcement learning are also predicted.
FRACTAL AND FRACTIONAL
(2022)
Article
Materials Science, Multidisciplinary
Son T. Le, Albert F. Rigosi, Joseph A. Hagmann, Christopher Gutierrez, Ji Ung Lee, Curt A. Richter
Summary: Interference patterns in the resistance of a graphene annulus p-n junction device caused by two separate gate voltages are observed and analyzed. It is found that the position of the resistance peaks resulting from these patterns is independent of temperature and magnetic field and cannot be attributed to known interference phenomena. Comparison with another device of a different topological class reveals subtle differences in the measured data, suggesting that quantum scarring is the most likely source of the observed geometric interference patterns.
Article
Cardiac & Cardiovascular Systems
Jacek Zawadzki, Grzegorz Zawadzki, Jadwiga Radziejewska, Peter-Stephan Wolff, Agnieszka Slawuta, Jacek Gajek
Summary: The study demonstrated that P-wave dispersion is an artifact of low accuracy in P wave measurement, with high precision measurement methods yielding different results compared to imprecise methods.
REVIEWS IN CARDIOVASCULAR MEDICINE
(2021)
Article
Physics, Multidisciplinary
Maximilian Kiefer-Emmanouilidis, Razmik Unanyan, Michael Fleischhauer, Jesko Sirker
Summary: We study quench dynamics in a t-V chain of spinless fermions with strong potential disorder and argue particles do not become fully localized, with no alternative interpretations found. Further insights into entanglement dynamics and particle fluctuations are obtained by comparing with noninteracting systems. Renormalized bounds in the interacting case support numerically discovered scaling relations between number and entanglement entropies.
Article
Physics, Multidisciplinary
Alexander Altland, Michael Fleischhauer, Sebastian Diehl
Summary: This study presents a complete symmetry classification of fermion matter in and out of thermal equilibrium, starting from the state transformations in fermionic Fock spaces and the invariance properties of the density matrix dynamical equation. The classification of generators of reversible dynamics, dissipation, and fluctuations in irreversible and interacting dynamical equations leads to a distinction between equilibrium and out-of-equilibrium symmetries, highlighting the role of time in each case. In the context of nonequilibrium quantum dynamics, a novel realization of antilinear symmetries is observed, fundamentally different from the rules of thermal equilibrium.
Article
Physics, Multidisciplinary
M. Will, G. E. Astrakharchik, M. Fleischhauer
Summary: The article presents a detailed study of heavy polarons in a one-dimensional Bose gas using a nonperturbative theory and exact numerical simulations. Analytic approaches for weak boson-boson interactions and strong impurity-boson couplings were developed, and the interaction potential of heavy polarons was found to deviate substantially from the exponential form in the strong coupling limit. Calculations of bipolaron binding energies for low impurity-boson mass ratios were in excellent agreement with quantum Monte Carlo results, taking into account Born-Huang corrections.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Simon Ohler, Maximilian Kiefer-Emmanouilidis, Antoine Browaeys, Hans Peter Buechler, Michael Fleischhauer
Summary: Investigation of properties in a one-dimensional zig-zag ladder system of spin-orbit coupled Rydberg atoms reveals an association between second-order hopping and effective gauge field, leading to the formation of current vortices.
NEW JOURNAL OF PHYSICS
(2022)
Article
Physics, Multidisciplinary
C. D. Mink, A. Pelster, J. Benary, H. Ott, M. Fleischhauer
Summary: The truncated Wigner approximation is a method for describing the dynamics of weakly interacting Bose gases. In this paper, a numerically inexpensive scheme is developed by approximating the c-number field, and its accuracy and efficiency are demonstrated by comparing predictions to experimental data.
Article
Physics, Multidisciplinary
Maximilian Kiefer-Emmanouilidis, Razmik Unanyan, Michael Fleischhauer, Jesko Sirker
Summary: In this study, we investigate and compare the particle number fluctuations in a spinless fermion model with potential disorder and nearest-neighbor interactions in the putative many-body localized (MBL) phase with those in the non-interacting case (Anderson localization) and in effective models where only interaction terms diagonal in the Anderson basis are kept. We demonstrate that these simple effective models cannot explain the particle number fluctuations observed in the MBL phase of the microscopic model.
Article
Physics, Multidisciplinary
Benjamin Nagler, Martin Will, Silvia Hiebel, Sian Barbosa, Jennifer Koch, Michael Fleischhauer, Artur Widera
Summary: We experimentally study the dissipative dynamics of ultracold bosonic gases in a dynamic disorder potential with tunable correlation time. Our results reveal the interplay between superfluidity and time-dependent disorder and establish ultracold atoms as a platform for studying spatiotemporal noise and time-dependent disorder.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
R. G. Unanyan, N. V. Vitanov, M. Fleischhauer
Summary: The Born-Fock theorem is a fundamental theorem in quantum mechanics that provides the basis for reliable and efficient navigation in the Hilbert space of a quantum system with a time-dependent Hamiltonian through adiabatic evolution. By controlling the eigenstates and their energetic order, perfect adiabatic transfer between initial and target states can be achieved. The fidelity of the state transfer is limited by adiabaticity, and the selection of target states is controlled by the integer invariant labeling the order of eigenstates. In this study, we demonstrate the adiabatic control of eigenstates in a finite superlattice Wannier-Stark ladder, resulting in perfectly quantized single-particle transport across a predetermined number of lattice sites. We dedicate this paper to the memory of our late friend and colleague Bruce Shore, who was an expert in adiabatic processes and greatly influenced our understanding in this field.
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Helene Wetter, Michael Fleischhauer, Stefan Linden, Julian Schmitt
Summary: This paper studies the dissipation-induced emergence of a topological band structure in a non-Hermitian one-dimensional lattice system using arrays of plasmonic waveguides with tailored loss, and provides direct evidence for a topological edge state residing in the center of the band gap.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Simon Ohler, Maximilian Kiefer-Emmanouilidis, Michael Fleischhauer
Summary: We investigate the nonlinear transport of bosonic excitations in a two-dimensional honeycomb lattice of spin-orbit-coupled Rydberg atoms, and find that it gives rise to topological disordered quantum phases. By using exact diagonalization (ED), we study the competition between density-dependent and direct transport terms as well as density-density interactions, and numerically determine the resulting phase diagram. We show the emergence of a new phase with large spin chirality and nontrivial many-body Chern number induced by the density dependence of the complex hopping.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Physics, Multidisciplinary
Christopher D. Mink, David Petrosyan, Michael Fleischhauer
Summary: In this study, we propose a systematic approach for the semiclassical treatment of many-body dynamics of interacting, open spin systems. This approach improves the classical treatment by accounting for lowest-order quantum fluctuations and overcomes some of the limitations of the existing discrete truncated Wigner approximation. By embedding the discrete truncated Wigner approximation in a continuous phase space, we derive an exact equation of motion for the continuous SU(2) Wigner function of spins. By neglecting specific terms in this exact equation of motion, we recover the standard discrete truncated Wigner approximation. This hybrid approach allows us to determine validity conditions and gain a detailed understanding of the approximation quality, paving the way for systematic improvements. We also demonstrate that the continuous embedding allows for an extension of the method to open spin systems subject to dephasing, losses, and incoherent drive.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Optics
Andreas F. Tzortzakakis, David Petrosyan, Michael Fleischhauer, Klaus Molmer
Summary: This study examines the adiabatic preparation of spatially ordered Rydberg excitations of atoms in finite one-dimensional lattices. It aims to unravel the microscopic mechanism of the phase transition and estimate the preparation fidelity of the target state. The study shows that the many-body system can be described as an effective two-level system and the final preparation fidelity can be approximated using the Landau-Zener formula.
Article
Materials Science, Multidisciplinary
Lukas Wawer, Michael Fleischhauer
Summary: The topological classification of fermion systems in mixed states has been a long-standing quest. Observable many-body correlators in mixed states preserve the quantized nature and naturally connect to known topological invariants in the ground state. A Z(2) topological invariant has been proposed for systems with time-reversal symmetry, which is identical to well-known Z(2) invariants for the ground state.
Article
Materials Science, Multidisciplinary
Lukas Wawer, Michael Fleischhauer
Summary: The study extends the concept of ensemble geometric phase to mixed states in two-dimensional band structures, introducing a proper Chern number calculation method for various types of states. The Chern number can be calculated through the ground-state Berry curvature of a fictitious Hamiltonian that breaks time-reversal symmetry.
Article
Optics
Lukas Wawer, Rui Li, Michael Fleischhauer
Summary: The study demonstrates that a topological pump in a one-dimensional insulator can cause strictly quantized transport in an auxiliary chain of noninteracting fermions, with the transported charge determined by an integer topological invariant of the insulator's fictitious Hamiltonian. This number is identical to the TKNN invariant of the original system in the case of noninteracting fermions, while in interacting systems, the transported charge defines a topological invariant. In certain cases, this invariant agrees with the many-body generalization of the TKNN number.