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Full-Text Articles in Physics

Doping A Lattice-Trapped Bosonic Species With Impurities: From Ground State Properties To Correlated Tunneling Dynamics, Kevin Keiler, Simeon I. Mistakidis, Peter Schmelcher Aug 2020

Doping A Lattice-Trapped Bosonic Species With Impurities: From Ground State Properties To Correlated Tunneling Dynamics, Kevin Keiler, Simeon I. Mistakidis, Peter Schmelcher

Physics Faculty Research & Creative Works

We Investigate The Ground State Properties And The Nonequilibrium Dynamics Of A Lattice Trapped Bosonic Mixture Consisting Of An Impurity Species And A Finite-Sized Medium. For The Case Of One As Well As Two Impurities We Observe That, Depending On The Lattice Depth And The Interspecies Interaction Strength, A Transition From A Strongly Delocalized To A Localized Impurity Distribution Occurs. In The Latter Regime The Two Species Phase Separate, Thereby Forming A Particle-Hole Pair. For Two Impurities We Find That Below A Critical Lattice Depth They Are Delocalized Among Two Neighboring Outer Lattice Wells And Are Two-Body Correlated. This Transition …


Entanglement-Assisted Tunneling Dynamics Of Impurities In A Double Well Immersed In A Bath Of Lattice Trapped Bosons, Friethjof Theel, Kevin Keiler, Simeon I. Mistakidis, Peter Schmelcher Jan 2020

Entanglement-Assisted Tunneling Dynamics Of Impurities In A Double Well Immersed In A Bath Of Lattice Trapped Bosons, Friethjof Theel, Kevin Keiler, Simeon I. Mistakidis, Peter Schmelcher

Physics Faculty Research & Creative Works

We Unravel The Correlated Tunneling Dynamics Of An Impurity Trapped In A Double Well And Interacting Repulsively With A Majority Species Of Lattice Trapped Bosons. Upon Quenching The Tilt Of The Double Well It Is Found That The Quench-Induced Tunneling Dynamics Depends Crucially On The Interspecies Interaction Strength And The Presence Of Entanglement Inherent In The System. In Particular, For Weak Couplings The Impurity Performs A Rather Irregular Tunneling Process In The Double Well. Increasing The Interspecies Coupling It Is Possible To Control The Response Of The Impurity Which Undergoes A Delayed Tunneling While The Majority Species Effectively Acts As …


Nonlinear Dynamics And Dissipation Of A Curvilinear Vortex Driven By A Strong Time-Dependent Meissner Current, W.P.M.R. Pathirana, A. Gurevich Jan 2020

Nonlinear Dynamics And Dissipation Of A Curvilinear Vortex Driven By A Strong Time-Dependent Meissner Current, W.P.M.R. Pathirana, A. Gurevich

Physics Faculty Publications

We report numerical simulations of large-amplitude oscillations of a trapped vortex line under a strong ac magnetic field H(t)=H sinωt parallel to the surface. The power dissipated by an oscillating vortex segment driven by the surface ac Meissner currents was calculated by taking into account the nonlinear vortex line tension, vortex mass, and a nonlinear Larkin-Ovchinnikov (LO) viscous drag coefficient η(v). We show that the LO decrease of η(v) with the vortex velocity v can radically change the field dependence of the surface resistance Ri(H) caused by trapped vortices. At low frequencies, …


Field-Dependent Nonlinear Surface Resistance And Its Optimization By Surface Nanostructuring In Superconductors, Takayuki Kubo, Alex Gurevich Jan 2019

Field-Dependent Nonlinear Surface Resistance And Its Optimization By Surface Nanostructuring In Superconductors, Takayuki Kubo, Alex Gurevich

Physics Faculty Publications

We propose a theory of nonlinear surface resistance of a dirty superconductor in a strong radio-frequency (rf) field, taking into account magnetic and nonmagnetic impurities, finite quasiparticle lifetimes, and a thin proximity-coupled normal layer characteristic of the oxide surface of many materials. The Usadel equations were solved to obtain the quasiparticle density of states (DOS) and the low-frequency surface resistance Rs as functions of the rf field amplitude H0. It is shown that the interplay of the broadening of the DOS peaks and a decrease of a quasiparticle gap caused by the rf currents produces a minimum …


Evidence For Terahertz Acoustic Phonon Parametric Oscillator Based On Acousto-Optic Degenerate Four-Wave Mixing In A Silicon Doping Superlattice, Thomas E. Wilson Dec 2018

Evidence For Terahertz Acoustic Phonon Parametric Oscillator Based On Acousto-Optic Degenerate Four-Wave Mixing In A Silicon Doping Superlattice, Thomas E. Wilson

Physics Faculty Research

We report evidence for a 1.0-THz self-starting mirrorless acoustic phonon parametric oscillator (MAPPO) produced from acousto-optic phase-conjugate degenerate four-wave (D4WM) mixing in a THz laser-pumped silicon doping superlattice (DSL). The DSL was grown by molecular beam epitaxy on a (100) boron-doped silicon substrate. A superconducting NbTiN subwavelength grating was used to couple the THz laser radiation into the DSL. Superconducting granular aluminum bolometric detection, coupled with Si:B piezophonon spectroscopy, revealed excitation of THz coherent compressional and shear waves, along the ⟨111⟩ direction only. The Bragg scattering condition for distributed feedback, and the energy conservation requirement for the D4WM process, were …


Analysis Of Adsorbed Contaminants Of Caf/Sub 2/ Surfaces By Infrared Laser Induced Desorption, Jinmei Fu, Yamini Surapaneni, Susan D. Allen Sep 2004

Analysis Of Adsorbed Contaminants Of Caf/Sub 2/ Surfaces By Infrared Laser Induced Desorption, Jinmei Fu, Yamini Surapaneni, Susan D. Allen

Mechanical Engineering - Daytona Beach

157 nm photolithography technologies are currently under development and have been accepted as the leading candidate for fabrication of the next generation semiconductor devices after 193 nm. At this and shorter wavelengths, molecular contamination of surfaces becomes a serious problem as almost all molecules absorb at 157 nm and below. The light transmitted by a photolithographic tool can be significantly decreased by the presence of a few monolayers adsorbed on its many optical surfaces. We have developed a laser induced desorption, electron impact ionization, time-of-flight mass spectrometer (LID TOFMS) to study contaminants on 157nm and other ultraviolet optics, e.g., polished …