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Articles 1 - 30 of 1742
Full-Text Articles in Physics
Instantons In Φ4 Theories: Transseries, Virial Theorems, And Numerical Aspects, Ludovico T. Giorgini, Ulrich D. Jentschura, Enrico M. Malatesta, Tommaso Rizzo, Jean Zinn-Justin
Instantons In Φ4 Theories: Transseries, Virial Theorems, And Numerical Aspects, Ludovico T. Giorgini, Ulrich D. Jentschura, Enrico M. Malatesta, Tommaso Rizzo, Jean Zinn-Justin
Physics Faculty Research & Creative Works
We discuss numerical aspects of instantons in two- and three-dimensional φ4 theories with an internal O(N) symmetry group, the so-called N-vector model. By combining asymptotic transseries expansions for large arguments with convergence acceleration techniques, we obtain high-precision values for certain integrals of the instanton that naturally occur in loop corrections around instanton configurations. Knowledge of these numerical properties is necessary in order to evaluate corrections to the large-order factorial growth of perturbation theory in φ4 theories. The results contribute to the understanding of the mathematical structures underlying the instanton configurations.
Perturbative Versus Non-Perturbative Renormalization, S. Hariharakrishnan, Ulrich D. Jentschura, I. G. Marian, K. Szabo, I. Nandori
Perturbative Versus Non-Perturbative Renormalization, S. Hariharakrishnan, Ulrich D. Jentschura, I. G. Marian, K. Szabo, I. Nandori
Physics Faculty Research & Creative Works
Approximated functional renormalization group (FRG) equations lead to regulator-dependent β-functions, in analogy to the scheme-dependence of the perturbative renormalization group (pRG) approach. A scheme transformation redefines the couplings to relate the β-functions of the FRG method with an arbitrary regulator function to the pRG ones obtained in a given scheme. Here, we consider a periodic sine-Gordon scalar field theory in d = 2 dimensions and show that the relation of the FRG and pRG approaches is intricate. Although both the FRG and the pRG methods are known to be sufficient to obtain the critical frequency β c 2 = 8 …
Doubly Differential Cross Sections For Ionization In Proton Collisions With Atomic Hydrogen: Energy And Angular Distribution Of Emitted Electrons, C. T. Plowman, K. H. Spicer, N. W. Antonio, M. S. Schöffler, Michael Schulz, I. Bray, A. S. Kadyrov
Doubly Differential Cross Sections For Ionization In Proton Collisions With Atomic Hydrogen: Energy And Angular Distribution Of Emitted Electrons, C. T. Plowman, K. H. Spicer, N. W. Antonio, M. S. Schöffler, Michael Schulz, I. Bray, A. S. Kadyrov
Physics Faculty Research & Creative Works
We use the two-center wave-packet convergent close-coupling approach to ion-atom collisions to calculate the energy and angular distribution of electrons emitted in proton collisions with atomic hydrogen. Results are provided across a wide range of intermediate energies where many competing reaction channels make calculations challenging. The present data consistently agree with the available experimental measurements and improve upon previously available results based on perturbative and classical methods. Furthermore, we extend the range of electron angles and energies over which theoretical data are available for the doubly differential cross section for ionization. This provides strong evidence that at the level of …
Particle-Imbalanced Weakly Interacting Quantum Droplets In One Dimension, I. A. Englezos, P. Schmelcher, S. I. Mistakidis
Particle-Imbalanced Weakly Interacting Quantum Droplets In One Dimension, I. A. Englezos, P. Schmelcher, S. I. Mistakidis
Physics Faculty Research & Creative Works
We explore the formation of one-dimensional two-component quantum droplets with intercomponent particle imbalance using an ab initio many-body method. It is shown that for moderate particle imbalance each component maintains its droplet flat-top or Gaussian-type character depending on the intercomponent attraction. Importantly, large particle imbalance leads to a flat-top shape of the majority component with the minority exhibiting spatially localized configurations. The latter imprint modulations on the majority component which become more pronounced for increasing interspecies attraction. The same holds for larger mass or increasing repulsion of the minority species. Such structural transitions are also evident in the underlying two-body …
Novel Emergent Phases In A Two-Dimensional Superconductor, Simrandeep Kaur, Hemanta Kumar Kundu, Sumit Kumar, Anjana Dogra, Rajesh Narayanan, Thomas Vojta, Aveek Bid
Novel Emergent Phases In A Two-Dimensional Superconductor, Simrandeep Kaur, Hemanta Kumar Kundu, Sumit Kumar, Anjana Dogra, Rajesh Narayanan, Thomas Vojta, Aveek Bid
Physics Faculty Research & Creative Works
In this letter, we report our observation of an extraordinarily rich phase diagram of a LaScO3/SrTiO3 heterostructure. Close to the superconducting transition temperature, the system hosts a superconducting critical point of the Infinite-randomness type characterized by an effective dynamical exponent ν z that diverges logarithmically. At lower temperatures, we find the emergence of a magnetic field-tuned metallic phase that co-exists with a quantum Griffiths phase (QGP). Our study reveals a previously unobserved phenomenon in 2D superconductors—an unanticipated suppression of the QGP below a crossover temperature in this system. This concealment is accompanied by the destruction of the …
Dispersive Shock Waves In A One-Dimensional Droplet-Bearing Environment, Sathyanarayanan Chandramouli, S. I. Mistakidis, G. C. Katsimiga, P. G. Kevrekidis
Dispersive Shock Waves In A One-Dimensional Droplet-Bearing Environment, Sathyanarayanan Chandramouli, S. I. Mistakidis, G. C. Katsimiga, P. G. Kevrekidis
Physics Faculty Research & Creative Works
We demonstrate the controllable generation of distinct types of dispersive shock waves emerging in a quantum droplet bearing environment with the aid of steplike initial conditions. Dispersive regularization of the ensuing hydrodynamic singularities occurs due to the competition between mean-field repulsion and attractive quantum fluctuations. This interplay delineates the dominance of defocusing (hyperbolic) and focusing (elliptic) hydrodynamic phenomena being designated by the real and the imaginary speed of sound, respectively. Specifically, the symmetries of the extended Gross-Pitaevskii model led to a three-parameter family, encompassing two densities and a relative velocity of the underlying Riemann problem utilized herein. Surprisingly, dispersive shock …
Dispersive Shock Waves In A One-Dimensional Droplet-Bearing Environment, Sathyanarayanan Chandramouli, S. I. Mistakidis, G. C. Katsimiga, P. G. Kevrekidis
Dispersive Shock Waves In A One-Dimensional Droplet-Bearing Environment, Sathyanarayanan Chandramouli, S. I. Mistakidis, G. C. Katsimiga, P. G. Kevrekidis
Physics Faculty Research & Creative Works
We demonstrate the controllable generation of distinct types of dispersive shock waves emerging in a quantum droplet bearing environment with the aid of steplike initial conditions. Dispersive regularization of the ensuing hydrodynamic singularities occurs due to the competition between mean-field repulsion and attractive quantum fluctuations. This interplay delineates the dominance of defocusing (hyperbolic) and focusing (elliptic) hydrodynamic phenomena being designated by the real and the imaginary speed of sound, respectively. Specifically, the symmetries of the extended Gross-Pitaevskii model led to a three-parameter family, encompassing two densities and a relative velocity of the underlying Riemann problem utilized herein. Surprisingly, dispersive shock …
Critical Behavior And Collective Modes At The Superfluid Transition In Amorphous Systems, Pulloor Kuttanikkad Vishnu, Martin Puschmann, Rajesh Narayanan, Thomas Vojta
Critical Behavior And Collective Modes At The Superfluid Transition In Amorphous Systems, Pulloor Kuttanikkad Vishnu, Martin Puschmann, Rajesh Narayanan, Thomas Vojta
Physics Faculty Research & Creative Works
We investigate the critical behavior and the dynamics of the amplitude (Higgs) mode close to the superfluid-insulator quantum phase transition in an amorphous system (i.e., a system subject to topological randomness). In particular, we map the two-dimensional Bose-Hubbard Hamiltonian defined on a random Voronoi-Delaunay lattice onto a (2+1)-dimensional layered classical XY model with correlated topological disorder. We study the resulting model by laying recourse to classical Monte Carlo simulations. We specifically focus on the scalar susceptibility of the order parameter to study the dynamics of the amplitude mode. To do so, we harness the maximum entropy method to perform the …
Eighth-Order Foldy-Wouthuysen Transformation, Ulrich D. Jentschura
Eighth-Order Foldy-Wouthuysen Transformation, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
The calculation of higher-order binding corrections to bound systems is a fundamental problem of theoretical physics. For any nonrelativistic expansion, one needs the Foldy-Wouthuysen transformation, which disentangles the particle and the antiparticle degrees of freedom. This transformation is carried out here to eighth order in the momenta or to eighth order in the momentum operators, which is equivalent to the eighth order of the fine-structure constant. Matrix elements of the eighth-order terms are evaluated for F5/2 and F7/2 states in hydrogenlike ions and compared with the Dirac-Coulomb energy levels.
Tunneling Dynamics Of 164dy Supersolids And Droplets, S. I. Mistakidis, K. Mukherjee, S. M. Reimann, H. R. Sadeghpour
Tunneling Dynamics Of 164dy Supersolids And Droplets, S. I. Mistakidis, K. Mukherjee, S. M. Reimann, H. R. Sadeghpour
Physics Faculty Research & Creative Works
The tunneling dynamics of a magnetic Dy164 quantum gas in an elongated or pancake skewed double-well trap is investigated with a time-dependent extended Gross-Pitaevskii approach. Upon lifting the energy offset, different tunneling regimes can be identified. In the elongated trap and for sufficiently large offset, the different configurations exhibit collective macroscopic tunneling. For smaller offset, partial reflection from and transmission through the barrier lead to density accumulation in both wells, and eventually to tunneling locking. One can also reach the macroscopic self-trapping regime for increasing relative dipolar interaction strength, while tunneling vanishes for large barrier heights. A richer dynamical behavior …
Magnetic Properties Of Diluted Hexaferrites, Logan Sowadski, Sean Anderson, Cameron Lerch, Julia E. Medvedeva, Thomas Vojta
Magnetic Properties Of Diluted Hexaferrites, Logan Sowadski, Sean Anderson, Cameron Lerch, Julia E. Medvedeva, Thomas Vojta
Physics Faculty Research & Creative Works
We revisit the magnetic properties of the hexagonal ferrite PbFe12-xGaxO19. Recent experiments have reported puzzling dependences of the ordering temperature and the saturation magnetization on the Ga concentration x. To explain these observations, we perform large-scale Monte Carlo simulations, focusing on the effects of an unequal distribution of the Ga impurities over the five distinct Fe sublattices. Ab initio density-functional calculations predict that the Ga ions preferably occupy the 12k sublattice and (to a lesser extent) the 2a sublattice. We incorporate this insight into a nonuniform model of the Ga distribution. Monte Carlo simulations …
Thermal Stability Of Amorphous Metal Oxides: The Interplay Of Secondary Cations, Degree Of Substitution, And Local Structure, Li Zeng, D. Bruce Buchholz, Denis T. Keane, Tobin J. Marks, Julia E. Medvedeva, Michael J. Bedzyk
Thermal Stability Of Amorphous Metal Oxides: The Interplay Of Secondary Cations, Degree Of Substitution, And Local Structure, Li Zeng, D. Bruce Buchholz, Denis T. Keane, Tobin J. Marks, Julia E. Medvedeva, Michael J. Bedzyk
Physics Faculty Research & Creative Works
Indium-based amorphous metal oxides (AMOs) are important materials that enable a wide range of electronic and optoelectronic applications. The metal cations that substitute for In are known to effectively tune the material properties as well as to retain the desirable amorphous state when subjected to high operating temperatures. While much attention focuses on property tuning, there is less focus on those fundamental factors that enhance thermal stability. Hence, in this paper, we employ in situ X-ray scattering and ab initio molecular dynamics (MD) to systematically study the effects of secondary cations on the crystallization process. A series of amorphous (In …
Ruling Out A Saddle-Point Mechanism Of Ionization In Intermediate-Energy Ion-Atom Collisions, K. H. Spicer, C. T. Plowman, N. W. Antonio, M. S. Schöffler, Michael Schulz, A. S. Kadyrov
Ruling Out A Saddle-Point Mechanism Of Ionization In Intermediate-Energy Ion-Atom Collisions, K. H. Spicer, C. T. Plowman, N. W. Antonio, M. S. Schöffler, Michael Schulz, A. S. Kadyrov
Physics Faculty Research & Creative Works
Is there a saddle-point mechanism for ionization in intermediate-energy ion-atom collisions Since Olson [Phys. Rev. A 33, 4397 (1986)0556-279110.1103/PhysRevA.33.4397] proposed the idea that the electrons stranded in the potential saddle between the two Coulomb centers dominate the ejected-electron spectra, multiple experimental and theoretical attempts have been made to answer this question. However, the topic has remained controversial. Here we provide a theoretical analysis of this question which can contribute significantly to a definitive answer, at least for intermediate and large projectile energies. To this end we calculate the energy and angular distribution of electrons emitted in proton-helium collisions. We use …
Scalar Susceptibility Of A Diluted Classical Xy Model, Reece Beattie-Hauser, Thomas Vojta
Scalar Susceptibility Of A Diluted Classical Xy Model, Reece Beattie-Hauser, Thomas Vojta
Physics Faculty Research & Creative Works
We Analyze the Amplitude Fluctuations in a Diluted 3D Classical XY Model Near the Magnetic Phase Transition, motivated by the Unusual Localization Properties of the Amplitude (Higgs) Mode Recently Found at the Disordered Superfluid-Mott Glass Quantum Phase Transition. We Calculate the Amplitude Correlation Function and the Corresponding Scalar Susceptibility by Means of Monte Carlo Simulations. in Contrast to the Quantum Case, in Which the Scalar Susceptibility Was Found to Violate Naive Scaling, We Find that the Scalar Susceptibility of the Classical System Fulfills Naive Scaling (Employing the Clean Critical Exponents, as Expected from the Harris Criterion) as the Temperature is …
Crystallographic Defects In Weyl Semimetal Laalge, Inseo Kim, Byungkyun Kang, Hyunsoo Kim, Minseok Choi
Crystallographic Defects In Weyl Semimetal Laalge, Inseo Kim, Byungkyun Kang, Hyunsoo Kim, Minseok Choi
Physics Faculty Research & Creative Works
Crystallographic Defects in a Topological Semimetal Can Result in Charge Doping and Scattering Centers Which May Mask the Exotic Spectroscopic and Transport Properties, respectively. Here, We Investigate the Possible Crystallographic Defects Including Vacancy and Antisite in Weyl Semimetal LaAlGe using Hybrid-Density-Functional Theory Calculations. We Show that a Considerable Concentration of Al- and Ge-Related Defects Naturally Form during Growth Due to their Low Formation Enthalpy. Specifically, Al Can Be Easily Replaced by Ge in the I41md Phase of LaAlGe, Forming the Ge-On-Al Antisite, GeAl. the Counterpart, Al-On-Ge (AlGe), is Also Probable. the Most Abundant Defect GeAl is Donorlike, Effectively Electron Doping, …
Dimensional Regularization And Two-Loop Vacuum Polarization Operator: Master Integrals, Analytic Results, And Energy Shifts, Stefano Laporta, Ulrich D. Jentschura
Dimensional Regularization And Two-Loop Vacuum Polarization Operator: Master Integrals, Analytic Results, And Energy Shifts, Stefano Laporta, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
We Present a Complete Reevaluation of the Irreducible Two-Loop Vacuum-Polarization Correction to the Photon Propagator in Quantum Electrodynamics, i.e. with an Electron-Positron Pair in the Fermion Propagators. the Integration is Carried Out by Reducing the Integrations to a Limited Set of Master Integrals, Which Are Calculated using Integration-By-Parts Identities. Dimensional Regularization is Used in D=4-2ϵ Dimensions, and On-Mass Shell Renormalization is Employed. the One-Loop Effect is Given to Order ϵ, to Be Combined with the 1/ϵ Divergence of the Two-Loop Amplitude. Master Integrals Are Given. Final Evaluations of Two-Loop Energy Shifts for 1S, 2S, and 2P States Are Done Analytically, …
Second Inflection Point Of Supercooled Water Surface Tension Induced By Hydrogen Bonds: A Molecular-Dynamics Study, Fawaz Hrahsheh, Inshad Jum'h, Gerald Wilemski
Second Inflection Point Of Supercooled Water Surface Tension Induced By Hydrogen Bonds: A Molecular-Dynamics Study, Fawaz Hrahsheh, Inshad Jum'h, Gerald Wilemski
Physics Faculty Research & Creative Works
Surface Tension Of Supercooled Water Is A Fundamental Property In Various Scientific Processes. In This Study, We Perform Molecular Dynamics Simulations With The TIP4P-2005 Model To Investigate The Surface Tension Of Supercooled Water Down To 220 K. Our Results Show A Second Inflection Point (SIP) In The Surface Tension At Temperature TSIP ≈ 267.5 ± 2.3 K. Using An Extended IAPWS-E Functional Fit For The Water Surface Tension, We Calculate The Surface Excess Internal-Energy And Entropy Terms Of The Excess Helmholtz Free Energy. Similar To Prior Studies [Wang Et Al., Phys. Chem. Chem. Phys. 21, 3360 (2019); Gorfer Et Al., …
Ionization Cross Sections Of Hydrogen Molecule By Electron And Positron Impact, Károly Tőkési, Robert D. Dubois
Ionization Cross Sections Of Hydrogen Molecule By Electron And Positron Impact, Károly Tőkési, Robert D. Dubois
Physics Faculty Research & Creative Works
We Present Ionization Cross Sections of Hydrogen Molecules by Electron and Positron Impact for Impact Energies between 20 and 1000 EV. a Three-Body Classical Trajectory Monte Carlo Approximation is Applied to Mimic the Collision System. in This Approach, the H2 Molecule is Modeled by a Hydrogen-Type Atom with One Active Electron Bound to a Central Core of Effective Charge with an Effective Binding Energy. Although This Model is Crude for Describing a Hydrogen Molecule, We Found that the Total Cross Sections for Positron Impact Agree Reasonably Well with the Experimental Data. for the Electron Impact, Our Calculated Cross Sections Are …
Universality Class Of A Spinor Bose–Einstein Condensate Far From Equilibrium, Seung Jung Huh, Koushik Mukherjee, Kiryang Kwon, Jihoon Seo, Junhyeok Hur, Simeon I. Mistakidis, H. R. Sadeghpour, Jae Yoon Choi
Universality Class Of A Spinor Bose–Einstein Condensate Far From Equilibrium, Seung Jung Huh, Koushik Mukherjee, Kiryang Kwon, Jihoon Seo, Junhyeok Hur, Simeon I. Mistakidis, H. R. Sadeghpour, Jae Yoon Choi
Physics Faculty Research & Creative Works
Scale Invariance And Self-Similarity In Physics Provide A Unified Framework For Classifying Phases Of Matter And Dynamical Properties Near Equilibrium In Both Classical And Quantum Systems. This Paradigm Has Been Further Extended To Isolated Many-Body Quantum Systems Driven Far From Equilibrium, For Which The Physical Observables Exhibit Dynamical Scaling With Universal Scaling Exponents. Universal Dynamics Appear In A Wide Range Of Scenarios, Including Cosmology, Quark–gluon Matter, Ultracold Atoms And Quantum Spin Magnets. However, How The Universal Dynamics Depend On The Symmetry Of The Underlying Hamiltonian In Non-Equilibrium Systems Remains An Outstanding Challenge. Here We Report On The Classification Of Universal …
Energy And Angular Distributions In 250 Ev Electron And Positron Collisions With Argon Atom, K. Tőkési, Robert D. Dubois
Energy And Angular Distributions In 250 Ev Electron And Positron Collisions With Argon Atom, K. Tőkési, Robert D. Dubois
Physics Faculty Research & Creative Works
We present energy and angular differential cross sections for single ionization in collisions between electrons and positrons with argon atoms at 250 eV. We treat the collision classically using the three-body approximation where the target atoms are described within the single active electron approximation using a Garvey model potential and only the outermost electron is involved in the collision dynamics. Our present classical trajectory Monte Carlo model is shown to describe the ionization cross sections reasonably well and agree with existing experimental data. We show that the energy distributions, both for electron and positron impact, have the same shape and …
Retardation Effects In Atom-Wall Interactions, T. Das, C. A. Ullrich, Ulrich D. Jentschura
Retardation Effects In Atom-Wall Interactions, T. Das, C. A. Ullrich, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
The onset of retardation effects in atom-wall interactions is studied. It is shown that the transition range from the 1/z3 short-range (van der Waals) interaction to the 1/z4 long-range (Casimir) retarded interaction critically depends on the atomic properties and on the dielectric function of the material. For simple non-alkali-metal atoms (e.g., ground-state hydrogen and ground-state helium) interacting with typical dielectric materials such as intrinsic silicon, the transition to the retarded regime is shown to proceed at a distance of about 10 nm (200 Bohr radii). This is much shorter than typical characteristic absorption wavelengths of solids. Larger transition regimes are …
Experimental Realization Of The Peregrine Soliton In Repulsive Two-Component Bose-Einstein Condensates, A. Romero-Ros, Garyfallia C. Katsimiga, Simeon I. Mistakidis, S. Mossman, G. Biondini, P. Schmelcher, P. Engels, P. G. Kevrekidis
Experimental Realization Of The Peregrine Soliton In Repulsive Two-Component Bose-Einstein Condensates, A. Romero-Ros, Garyfallia C. Katsimiga, Simeon I. Mistakidis, S. Mossman, G. Biondini, P. Schmelcher, P. Engels, P. G. Kevrekidis
Physics Faculty Research & Creative Works
We Experimentally Realize the Peregrine Soliton in a Highly Particle-Imbalanced Two-Component Repulsive Bose-Einstein Condensate in the Immiscible Regime. The Effective Focusing Dynamics and Resulting Modulational Instability of the Minority Component Provide the Opportunity to Dynamically Create a Peregrine Soliton with the Aid of an Attractive Potential Well That Seeds the Initial Dynamics. The Peregrine Soliton Formation Is Highly Reproducible, And Our Experiments Allow Us to Separately Monitor the Minority and Majority Components, And to Compare with the Single Component Dynamics in the Absence or Presence of the Well with Varying Depths. We Showcase the Centrality of Each of the Ingredients …
Quantum Scars And Regular Eigenstates In A Chaotic Spinor Condensate, Bertrand Evrard, Andrea Pizzi, Simeon I. Mistakidis, Ceren B. Dag
Quantum Scars And Regular Eigenstates In A Chaotic Spinor Condensate, Bertrand Evrard, Andrea Pizzi, Simeon I. Mistakidis, Ceren B. Dag
Physics Faculty Research & Creative Works
Quantum Many-Body Scars Consist Of A Few Low-Entropy Eigenstates In An Otherwise Chaotic Many-Body Spectrum, And Can Weakly Break Ergodicity Resulting In Robust Oscillatory Dynamics. The Notion Of Quantum Many-Body Scars Follows The Original Single-Particle Scars Introduced Within The Context Of Quantum Billiards, Where Scarring Manifests In The Form Of A Quantum Eigenstate Concentrating Around An Underlying Classical Unstable Periodic Orbit. A Direct Connection Between These Notions Remains An Outstanding Problem. Here, We Study A Many-Body Spinor Condensate That, Owing To Its Collective Interactions, Is Amenable To The Diagnostics Of Scars. We Characterize The System's Rich Dynamics, Spectrum, And Phase …
Two-Center And Path Interference In Dissociative Capture In P+ H2 Collisions, S. Bastola, M. Dhital, B. Lamichhane, A. Silvus, R. Lomsadze, A. Hasan, A. Igarashi, Michael Schulz
Two-Center And Path Interference In Dissociative Capture In P+ H2 Collisions, S. Bastola, M. Dhital, B. Lamichhane, A. Silvus, R. Lomsadze, A. Hasan, A. Igarashi, Michael Schulz
Physics Faculty Research & Creative Works
We have measured and calculated fully differential cross sections (FDCS) for dissociative capture in 75-keV p+H2 collisions. FDCS were analyzed in the kinetic energy release (KER) ranges 0 to 2.1 eV and 4 to 7 eV for two different molecular orientations. In the latter range, dissociation is dominated by electronic excitation to the 2pπu state. Here, we observed two-center interference for an orientation in the plane perpendicular to the initial beam axis and parallel to the transverse momentum transfer. The interference pattern is afflicted with a constant phase shift of π. In the range KER=0 to 2.1 eV, dissociation is …
Spectrum And Quench-Induced Dynamics Of Spin-Orbit-Coupled Quantum Droplets, Sonali Gangwar, Rajamanickam Ravisankar, S. (Simeon) I. Mistakidis, Paulsamy Muruganandam, Pankaj Kumar Mishra
Spectrum And Quench-Induced Dynamics Of Spin-Orbit-Coupled Quantum Droplets, Sonali Gangwar, Rajamanickam Ravisankar, S. (Simeon) I. Mistakidis, Paulsamy Muruganandam, Pankaj Kumar Mishra
Physics Faculty Research & Creative Works
We investigate the ground state and dynamics of one-dimensional spin-orbit coupled (SOC) quantum droplets within the extended Gross-Pitaevskii approach. As the SOC wave number increases, stripe droplet patterns emerge, with a flat-top background, for larger particle numbers. The surface energy decays following a power-law with respect to the interactions. At small SOC wave numbers, a transition from Gaussian to flat-top droplets occurs for either a larger number of atoms or reduced intercomponent attraction. The excitation spectrum shows that droplets for relatively small SOC wave numbers are stable, otherwise stripe droplets feature instabilities as a function of the particle number or …
Revisiting The Divergent Multipole Expansion Of Atom-Surface Interactions: Hydrogen And Positronium, Α -Quartz, And Physisorption, Ulrich D. Jentschura
Revisiting The Divergent Multipole Expansion Of Atom-Surface Interactions: Hydrogen And Positronium, Α -Quartz, And Physisorption, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
We revisit the derivation of multipole contributions to the atom-wall interaction previously presented in Łach et al. [G. Łach, M. DeKieviet, and U. D. Jentschura, Phys. Rev. A 81, 052507 (2010)10.1103/PhysRevA.81.052507]. A careful reconsideration of the angular momentum decomposition of the second-, third-, and fourth-rank tensors composed of the derivatives of the electric-field modes leads to a modification for the results for the quadrupole, octupole, and hexadecupole contributions to the atom-wall interaction. Asymptotic results are given for the asymptotic long-range forms of the multipole terms, in both the short-range and long-range limits. Calculations are carried out for hydrogen and positronium …
Many-Body Quantum Chaos In Stroboscopically-Driven Cold Atoms, Ceren B. Dağ, Simeon I. Mistakidis, Amos Chan, H. R. Sadeghpour
Many-Body Quantum Chaos In Stroboscopically-Driven Cold Atoms, Ceren B. Dağ, Simeon I. Mistakidis, Amos Chan, H. R. Sadeghpour
Physics Faculty Research & Creative Works
In Quantum Chaotic Systems, The Spectral Form Factor (SFF), Defined As The Fourier Transform Of Two-Level Spectral Correlation Function, Is Known To Follow Random Matrix Theory (RMT), Namely A 'ramp' Followed By A 'plateau' In Late Times. Recently, A Generic Early-Time Deviation From RMT, So-Called The 'bump', Was Shown To Exist In Random Quantum Circuits As Toy Models For Many-Body Quantum Systems. We Demonstrate The Existence Of 'bump-Ramp-Plateau' Behavior In The SFF For A Number Of Paradigmatic And Stroboscopically-Driven 1D Cold-Atom Models: Spinless And Spin-1/2 Bose-Hubbard Models, And Nonintegrable Spin-1 Condensate With Contact Or Dipolar Interactions. We Find That The …
Interferometry Of Efimov States In Thermal Gases By Modulated Magnetic Fields, G. Bougas, Simeon I. Mistakidis, P. Schmelcher, C. H. Greene, P. Giannakeas
Interferometry Of Efimov States In Thermal Gases By Modulated Magnetic Fields, G. Bougas, Simeon I. Mistakidis, P. Schmelcher, C. H. Greene, P. Giannakeas
Physics Faculty Research & Creative Works
We Demonstrate That An Interferometer Based On Modulated Magnetic Field Pulses Enables Precise Characterization Of The Energies And Lifetimes Of Efimov Trimers Irrespective Of The Magnitude And Sign Of The Interactions In Rb85 Thermal Gases. Despite Thermal Effects, Interference Fringes Develop When The Dark Time Between The Pulses Is Varied. This Enables The Selective Excitation Of Coherent Superpositions Of Trimer, Dimer, And Free-Atom States. The Interference Patterns Possess Two Distinct Damping Timescales At Short And Long Dark Times That Are Either Equal To Or Twice As Long As The Lifetime Of Efimov Trimers, Respectively. Specifically, This Behavior At Long Dark …
Interactions And Dynamics Of One-Dimensional Droplets, Bubbles And Kinks, Garyfallia Katsimiga, Simeon I. Mistakidis, Boris A. Malomed, Dimitris J. Frantzeskakis, Ricardo Carretero-Gonzalez, Panayotis G. Kevrekidis
Interactions And Dynamics Of One-Dimensional Droplets, Bubbles And Kinks, Garyfallia Katsimiga, Simeon I. Mistakidis, Boris A. Malomed, Dimitris J. Frantzeskakis, Ricardo Carretero-Gonzalez, Panayotis G. Kevrekidis
Physics Faculty Research & Creative Works
We Explore The Dynamics And Interactions Of Multiple Bright Droplets And Bubbles, As Well As The Interactions Of Kinks With Droplets And With Antikinks, In The Extended One-Dimensional Gross–Pitaevskii Model Including The Lee–Huang–Yang Correction. Existence Regions Are Identified For The One-Dimensional Droplets And Bubbles In Terms Of Their Chemical Potential, Verifying The Stability Of The Droplets And Exposing The Instability Of The Bubbles. The Limiting Case Of The Droplet Family Is A Stable Kink. The Interactions Between Droplets Demonstrate In-Phase (Out-Of-Phase) Attraction (Repulsion), With The So-Called Manton's Method Explicating The Observed Dynamical Response, And Mixed Behavior For Intermediate Values Of …
Quantum Electrodynamic Corrections To Cyclotron States In A Penning Trap, Ulrich D. Jentschura, Christopher Moore
Quantum Electrodynamic Corrections To Cyclotron States In A Penning Trap, Ulrich D. Jentschura, Christopher Moore
Physics Faculty Research & Creative Works
We analyze the leading and higher-order quantum electrodynamic corrections to the energy levels for a single electron bound in a Penning trap, including the Bethe logarithm correction due to virtual excitations of the reference quantum cyclotron state. The effective coupling parameter αc in the Penning trap is identified as the square root of the ratio of the cyclotron frequency, converted to an energy via multiplication by the Planck constant, to the electron rest mass energy. We find a large, state-independent, logarithmic one-loop self-energy correction of order α αc4mc2ln(αc-2), where m is the …