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Articles 241 - 270 of 1762
Full-Text Articles in Physical Sciences and Mathematics
Quench Dynamics Of Finite Bosonic Ensembles In Optical Lattices With Spatially Modulated Interactions, T. Plaßmann, Simeon I. Mistakidis, P. Schmelcher
Quench Dynamics Of Finite Bosonic Ensembles In Optical Lattices With Spatially Modulated Interactions, T. Plaßmann, Simeon I. Mistakidis, P. Schmelcher
Physics Faculty Research & Creative Works
The Nonequilibrium Quantum Dynamics Of Few Boson Ensembles Which Experience A Spatially Modulated Interaction Strength And Are Confined In Finite Optical Lattices Is Investigated. We Utilize A Cosinusoidal Spatially Modulated Effective Interaction Strength Which Is Characterized By Its Wavevector, Inhomogeneity Amplitude, Interaction Offset And A Phase. Performing Quenches Either On The Wavevector Or The Phase Of The Interaction Profile An Enhanced Imbalance Of The Interatomic Repulsion Between Distinct Spatial Regions Of The Lattice Is Induced. Following Both Quench Protocols Triggers Various Tunneling Channels And A Rich Excitation Dynamics Consisting Of A Breathing And A Cradle Mode. All Modes Are Shown …
Gw170817: Measurements Of Neutron Star Radii And Equation Of State, B. P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Gw170817: Measurements Of Neutron Star Radii And Equation Of State, B. P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were …
Real-Time Observation Of Molecular Spinning With Angular High-Harmonic Spectroscopy, Lixin He, Pengfei Lan, Anh-Thu Le, Baoning Wang, Bincheng Wang, Xiaosong Zhu, Peixiang Lu, C. D. Lin
Real-Time Observation Of Molecular Spinning With Angular High-Harmonic Spectroscopy, Lixin He, Pengfei Lan, Anh-Thu Le, Baoning Wang, Bincheng Wang, Xiaosong Zhu, Peixiang Lu, C. D. Lin
Physics Faculty Research & Creative Works
We demonstrate an angular high-harmonic spectroscopy method to probe the spinning dynamics of a molecular rotation wave packet in real time. With the excitation of two time-delayed, polarization-skewed pump pulses, the molecular ensemble is impulsively kicked to rotate unidirectionally, which is subsequently irradiated by another delayed probe pulse for high-order harmonic generation (HHG). The spatiotemporal evolution of the molecular rotation wave packet is visualized from the time-dependent angular distributions of the HHG yields and frequency shift measured at various polarization directions and time delays of the probe pulse. The observed frequency shift in HHG is demonstrated to arise from the …
Gravitational Effects In G -Factor Measurements And High-Precision Spectroscopy: Limits Of Einstein's Equivalence Principle, Ulrich D. Jentschura
Gravitational Effects In G -Factor Measurements And High-Precision Spectroscopy: Limits Of Einstein's Equivalence Principle, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
We study the interplay of general relativity, the equivalence principle, and high-precision experiments involving atomic transitions and g-factor measurements. In particular, we derive a generalized Dirac Hamiltonian, which describes both the gravitational coupling for weak fields and the electromagnetic coupling, e.g., to a central Coulomb field. An approximate form of this Hamiltonian is used to derive the leading gravitational corrections to transition frequencies and g factors. The position dependence of atomic transitions is shown to be compatible with the equivalence principle, up to a very good approximation. The compatibility of g-factor measurements requires a deeper subtle analysis in order to …
Electronic Fingerprints Of Cr And V Dopants In The Topological Insulator Sb₂Te₃, Wenhan Zhang, Damien West, Seng Huat Lee, Yunsheng Qiu, Cui-Zu Chang, Jagadeesh S. Moodera, Yew San Hor, Shengbai Zhang, Weida Wu
Electronic Fingerprints Of Cr And V Dopants In The Topological Insulator Sb₂Te₃, Wenhan Zhang, Damien West, Seng Huat Lee, Yunsheng Qiu, Cui-Zu Chang, Jagadeesh S. Moodera, Yew San Hor, Shengbai Zhang, Weida Wu
Physics Faculty Research & Creative Works
By combining scanning tunneling microscopy/spectroscopy and first-principles calculations, we systematically study the local electronic states of magnetic dopants V and Cr in the topological insulator (TI) Sb2Te3. Spectroscopic imaging shows diverse local defect states between Cr and V, which agree with our first-principle calculations. The unique spectroscopic features of V and Cr dopants provide electronic fingerprints for the codoped magnetic TI samples with the enhanced quantum anomalous Hall effect. Our results also facilitate the exploration of the underlying mechanism of the enhanced quantum anomalous Hall temperature in Cr/V codoped TIs.
Tunnel Diode Resonator For Precision Magnetic Susceptibility Measurements In A Mk Temperature Range And Large Dc Magnetic Fields, Hyunsoo Kim, M. A. Tanatar, R. Prozorov
Tunnel Diode Resonator For Precision Magnetic Susceptibility Measurements In A Mk Temperature Range And Large Dc Magnetic Fields, Hyunsoo Kim, M. A. Tanatar, R. Prozorov
Physics Faculty Research & Creative Works
Precision radio-frequency measurements of the magnetic susceptibility using the tunnel diode resonator (TDR) technique are used to study the delicate effects in magnetic and superconducting materials. High resolution (in ppb range) measurements are particularly important for studies of the London and Campbell penetration depths in a superconductor and for the investigation of magnetic transitions in (anti)ferromagnets. Due to the small rf magnetic-excitation in a mOe range, the TDR is especially useful at low-temperatures in a mK range, if Joule heating generated in the TDR circuitry is efficiently removed and the circuit is stabilized with sub-mK precision. Unfortunately, the circuit has …
Quantum Critical Behavior Of A Three-Dimensional Superfluid-Mott Glass Transition, Jack Crewse, Cameron Lerch, Thomas Vojta
Quantum Critical Behavior Of A Three-Dimensional Superfluid-Mott Glass Transition, Jack Crewse, Cameron Lerch, Thomas Vojta
Physics Faculty Research & Creative Works
The superfluid to insulator quantum phase transition of a three-dimensional particle-hole symmetric system of disordered bosons is studied. To this end, a site-diluted quantum rotor Hamiltonian is mapped onto a classical (3+1)-dimensional XY model with columnar disorder and analyzed by means of large-scale Monte Carlo simulations. The superfluid-Mott insulator transition of the clean, undiluted system is in the four-dimensional XY universality class and shows mean-field critical behavior with logarithmic corrections. The clean correlation length exponent ν=1/2 violates the Harris criterion, indicating that disorder must be a relevant perturbation. For nonzero dilutions below the lattice percolation threshold of pc=0.688392, …
The Role Of Multiple Electron Processes For Fast Ion H₂O Collisions, N. Bachi, G. S. Otero, S. Otranto, Ronald E. Olson
The Role Of Multiple Electron Processes For Fast Ion H₂O Collisions, N. Bachi, G. S. Otero, S. Otranto, Ronald E. Olson
Physics Faculty Research & Creative Works
In this work, collision processes between C6+, O8+ and Si13+ ions and H2O molecules that lead to target ionization are studied by means of the classical trajectory Monte Carlo method. We employ an 8-electron model in which the H2O electron densities and energies dynamically adapt during ionization processes to those corresponding to the H2Oq+ ions by assuming vertical transitions between the different molecular ionic states. Net total ionization cross sections and single differential cross sections in energy and angle are shown for 4 MeV/u projectiles and compared to available …
Extinction Transitions In Correlated External Noise, Alexander H. O. Wada, Matthew Small, Thomas Vojta
Extinction Transitions In Correlated External Noise, Alexander H. O. Wada, Matthew Small, Thomas Vojta
Physics Faculty Research & Creative Works
We analyze the influence of long-range correlated (colored) external noise on extinction phase transitions in growth and spreading processes. Uncorrelated environmental noise (i.e., temporal disorder) was recently shown to give rise to an unusual infinite-noise critical point [Europhys. Lett. 112, 30002 (2015)EULEEJ0295-507510.1209/0295-5075/112/30002]. It is characterized by enormous density fluctuations that increase without limit at criticality. As a result, a typical population decays much faster than the ensemble average, which is dominated by rare events. Using the logistic evolution equation as an example, we show here that positively correlated (red) environmental noise further enhances these effects. This means, the correlations accelerate …
Scanning Tunneling Spectroscopy Investigations Of Superconducting-Doped Topological Insulators: Experimental Pitfalls And Results, Stefan Wilfert, Paolo Sessi, Zhiwei Wang, Henrik Schmidt, M. Carmen Martínez-Velarte, Seng Huat Lee, Yew San Hor, Alexander F. Otte, Yoichi Ando, Weida Wu, Matthias Bode
Scanning Tunneling Spectroscopy Investigations Of Superconducting-Doped Topological Insulators: Experimental Pitfalls And Results, Stefan Wilfert, Paolo Sessi, Zhiwei Wang, Henrik Schmidt, M. Carmen Martínez-Velarte, Seng Huat Lee, Yew San Hor, Alexander F. Otte, Yoichi Ando, Weida Wu, Matthias Bode
Physics Faculty Research & Creative Works
Recently, the doping of topological insulators has attracted significant interest as a potential route towards topological superconductivity. Because many experimental techniques lack sufficient surface sensitivity, however, definite proof of the coexistence of topological surface states and surface superconductivity is still outstanding. Here we report on highly surface sensitive scanning tunneling microscopy and spectroscopy experiments performed on Tl-doped Bi2Te3, a three-dimensional topological insulator which becomes superconducting in the bulk at TC=2.3 K. Landau level spectroscopy as well as quasiparticle interference mapping clearly demonstrated the presence of a topological surface state with a Dirac point energy …
Tuning A Random-Field Mechanism In A Frustrated Magnet, Shashikant Singh Kunwar, Arnab Sen, Thomas Vojta, Rajesh Narayanan
Tuning A Random-Field Mechanism In A Frustrated Magnet, Shashikant Singh Kunwar, Arnab Sen, Thomas Vojta, Rajesh Narayanan
Physics Faculty Research & Creative Works
We study the influence of spinless impurities on a frustrated magnet featuring a spin-density wave (stripe) phase by means of Monte Carlo simulations. We demonstrate that the interplay between the impurities and an order parameter that breaks a real-space symmetry triggers the emergence of a random-field mechanism which destroys the stripe-ordered phase. Importantly, the strength of the emerging random fields can be tuned by the repulsion between the impurity atoms; they vanish for perfect anticorrelations between neighboring impurities. This provides a way of controlling the phase diagram of a many-particle system. In addition, we also investigate the effects of the …
Evolution Of Structure And Superconductivity In Ba(Ni₁₋ₓcoₓ)₂As₂, Chris Eckberg, Limin Wang, Halyna Hodovanets, Hyunsoo Kim, Daniel J. Campbell, Peter Zavalij, Philip Piccoli, Johnpierre Paglione
Evolution Of Structure And Superconductivity In Ba(Ni₁₋ₓcoₓ)₂As₂, Chris Eckberg, Limin Wang, Halyna Hodovanets, Hyunsoo Kim, Daniel J. Campbell, Peter Zavalij, Philip Piccoli, Johnpierre Paglione
Physics Faculty Research & Creative Works
The effects of Co substitution on Ba(Ni1-xCox)2As2 (0 ≤ x ≤ 0.251) single crystals grown out of Pb flux are investigated via transport, magnetic, and thermodynamic measurements. BaNi2As2 exhibits a first-order tetragonal to triclinic structural phase transition at Ts = 137 K upon cooling, and enters a superconducting phase below Tc = 0.7 K. The structural phase transition is sensitive to cobalt content and is suppressed completely by x ≥ 0.133. The superconducting critical temperature, Tc, increases continuously with x, reaching a maximum of Tc …
Relativistic And Radiative Corrections To The Dynamic Stark Shift: Gauge Invariance And Transition Currents In The Velocity Gauge, Ulrich D. Jentschura, Chandra M. Adhikari
Relativistic And Radiative Corrections To The Dynamic Stark Shift: Gauge Invariance And Transition Currents In The Velocity Gauge, Ulrich D. Jentschura, Chandra M. Adhikari
Physics Faculty Research & Creative Works
We investigate the gauge invariance of the dynamic (ac) Stark shift under "hybrid" gauge transformations from the "length" (E·r ) to the "velocity" (A-·p ) gauge. By a "hybrid" gauge transformation, we understand a transformation in which the scalar and vector potentials are modified, but the wave function remains unaltered. The gauge invariance of the leading term is well known, while we here show that gauge invariance under perturbations holds only if one takes into account an additional correction to the transition current, which persists only in the velocity gauge. We find a general expression for this current, and apply …
Dynamic Effects In Electron Momentum Spectroscopy Of Sulfur Hexafluoride, Xing Wang, Shenyue Xu, Chuangang Ning, O. Al-Hagan, Pengfei Hu, Yongtao Zhao, Zhongfen Xu, Jingkang Deng, Enliang Wang, Xueguang Ren, Alexander Dorn, Don H. Madison
Dynamic Effects In Electron Momentum Spectroscopy Of Sulfur Hexafluoride, Xing Wang, Shenyue Xu, Chuangang Ning, O. Al-Hagan, Pengfei Hu, Yongtao Zhao, Zhongfen Xu, Jingkang Deng, Enliang Wang, Xueguang Ren, Alexander Dorn, Don H. Madison
Physics Faculty Research & Creative Works
Electron momentum spectroscopy (EMS) results are presented for the sulfur hexafluoride (SF6) molecule using a high-resolution binary (e, 2e) spectrometer at incident energies (Ei) of 600, 1200, and 2400 eV plus the binding energy. The valence orbital momentum profiles were measured with a binding energy resolution of 0.68 eV and angular resolutions of Δθ = ±0.6⁰, ΔΦ = ±0.85⁰. Whereas the two higher incident energies are in the range where normally EMS measurements do not exhibit an impact-energy dependence, the current experimental data display a dynamic dependence on the impact energies. The measured momentum profiles are compared with predictions from …
Many-Body Expansion Dynamics Of A Bose-Fermi Mixture Confined In An Optical Lattice, P. Siegl, Simeon I. Mistakidis, P. Schmelcher
Many-Body Expansion Dynamics Of A Bose-Fermi Mixture Confined In An Optical Lattice, P. Siegl, Simeon I. Mistakidis, P. Schmelcher
Physics Faculty Research & Creative Works
We Unravel The Correlated Nonequilibrium Dynamics Of A Mass Balanced Bose-Fermi Mixture In A One-Dimensional Optical Lattice Upon Quenching An Imposed Harmonic Trap From Strong To Weak Confinement. Regarding The System's Ground State, The Competition Between The Inter- And Intraspecies Interaction Strength Gives Rise To The Immiscible And Miscible Phases Characterized By Negligible And Complete Overlap Of The Constituting Atomic Clouds, Respectively. The Resulting Dynamical Response Depends Strongly On The Initial Phase And Consists Of An Expansion Of Each Cloud And An Interwell Tunneling Dynamics. For Varying Quench Amplitude And Referring To A Fixed Phase, A Multitude Of Response Regimes …
Coas: The Line Of 3d Demarcation, Daniel J. Campbell, Limin Wang, Chris Eckberg, Dave Graf, Halyna Hodovanets, Johnpierre Paglione
Coas: The Line Of 3d Demarcation, Daniel J. Campbell, Limin Wang, Chris Eckberg, Dave Graf, Halyna Hodovanets, Johnpierre Paglione
Physics Faculty Research & Creative Works
Transition metal-pnictide compounds have received attention for their tendency to combine magnetism and unconventional superconductivity. Binary CoAs lies on the border of paramagnetism and the more complex behavior seen in isostructural CrAs, MnP, FeAs, and FeP. Here we report the properties of CoAs single crystals grown with two distinct techniques along with density functional theory calculations of its electronic structure and magnetic ground state. While all indications are that CoAs is paramagnetic, both experiment and theory suggest proximity to a ferromagnetic instability. Quantum oscillations are seen in torque measurements up to 31.5 T and support the calculated paramagnetic Fermiology.
Constraints On Cosmic Strings Using Data From The First Advanced Ligo Observing Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Constraints On Cosmic Strings Using Data From The First Advanced Ligo Observing Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
Cosmic strings are topological defects which can be formed in grand unified theory scale phase transitions in the early universe. They are also predicted to form in the context of string theory. The main mechanism for a network of Nambu-Goto cosmic strings to lose energy is through the production of loops and the subsequent emission of gravitational waves, thus offering an experimental signature for the existence of cosmic strings. Here we report on the analysis conducted to specifically search for gravitational-wave bursts from cosmic string loops in the data of Advanced LIGO 2015-2016 observing run (O1). No evidence of such …
Full Band All-Sky Search For Periodic Gravitational Waves In The O1 Ligo Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Full Band All-Sky Search For Periodic Gravitational Waves In The O1 Ligo Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We report on a new all-sky search for periodic gravitational waves in the frequency band 475-2000 Hz and with a frequency time derivative in the range of [-1.0,+0.1] x 10-8 Hz/s. Potential signals could be produced by a nearby spinning and slightly nonaxisymmetric isolated neutron star in our Galaxy. This search uses the data from Advanced LIGO's first observational run O1. No gravitational-wave signals were observed, and upper limits were placed on their strengths. For completeness, results from the separately published low-frequency search 20-475 Hz are included as well. Our lowest upper limit on worst-case (linearly polarized) strain amplitude …
Search For Tensor, Vector, And Scalar Polarizations In The Stochastic Gravitational-Wave Background, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For Tensor, Vector, And Scalar Polarizations In The Stochastic Gravitational-Wave Background, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find …
Dark-Bright Soliton Pairs: Bifurcations And Collisions, Garyfallia C. Katsimiga, P. G. Kevrekidis, B. Prinari, G. Biondini, P. Schmelcher
Dark-Bright Soliton Pairs: Bifurcations And Collisions, Garyfallia C. Katsimiga, P. G. Kevrekidis, B. Prinari, G. Biondini, P. Schmelcher
Physics Faculty Research & Creative Works
The statics, stability, and dynamical properties of dark-bright soliton pairs are investigated here, motivated by applications in a homogeneous two-component repulsively interacting Bose-Einstein condensate. One of the intraspecies interaction coefficients is used as the relevant parameter controlling the deviation from the integrable Manakov limit. Two different families of stationary states are identified consisting of dark-bright solitons that are either antisymmetric (out-of-phase) or asymmetric (mass imbalanced) with respect to their bright soliton. Both of the above dark-bright configurations coexist at the integrable limit of equal intra and interspecies repulsions and are degenerate in that limit. However, they are found to bifurcate …
Reduction Of The Ordered Magnetic Moment And Its Relationship To Kondo Coherence In Ce₁₋ₓlaₓcu₂Ge₂, B. G. Ueland, N. H. Jo, A. Sapkota, W. Tian, M. Masters, Halyna Hodovanets, S. S. Downing, C. Schmidt, R. J. Mcqueeney, For Full List Of Authors, See Publisher's Website.
Reduction Of The Ordered Magnetic Moment And Its Relationship To Kondo Coherence In Ce₁₋ₓlaₓcu₂Ge₂, B. G. Ueland, N. H. Jo, A. Sapkota, W. Tian, M. Masters, Halyna Hodovanets, S. S. Downing, C. Schmidt, R. J. Mcqueeney, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
The microscopic details of the suppression of antiferromagnetic order in the Kondo-lattice series Ce1-xLaxCu2Ge2 due to nonmagnetic dilution by La are revealed through neutron diffraction results for x = 0.20, 0.40, 0.75, and 0.85. Magnetic Bragg peaks are found for 0.20 ≤ x ≤ 0.75, and both the Néel temperature TN and the ordered magnetic moment per Ce μ linearly decrease with increasing x. The reduction in μ points to strong hybridization of the increasingly diluted Ce 4f electrons, and we find a remarkable quadratic dependence of μ on the Kondo-coherence temperature. We …
Beyond Triplet: Unconventional Superconductivity In A Spin-3/2 Topological Semimetal, Hyunsoo Kim, Kefeng Wang, Yasuyuki Nakajima, Rongwei Hu, Steven Ziemak, Paul Syers, Limin Wang, Halyna Hodovanets, Jonathan D. Denlinger, For Full List Of Authors, See Publisher's Website.
Beyond Triplet: Unconventional Superconductivity In A Spin-3/2 Topological Semimetal, Hyunsoo Kim, Kefeng Wang, Yasuyuki Nakajima, Rongwei Hu, Steven Ziemak, Paul Syers, Limin Wang, Halyna Hodovanets, Jonathan D. Denlinger, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
In all known fermionic superfluids, Cooper pairs are composed of spin-1/2 quasi-particles that pair to form either spin-singlet or spin-triplet bound States. The "spin" of a Bloch electron, however, is fixed by the symmetries of the crystal and the atomic orbitals from which it is derived and, in some cases, can behave as if it were a spin-3/2 particle. The superconducting state of such a system allows pairing beyond spin-triplet, with higher spin quasi-particles combining to form quintet or septet pairs. We report evidence of unconventional superconductivity emerging from a spin-3/2 quasi-particle electronic structure in the half-Heusler semimetal YPtBi, a …
Following Coherent Multichannel Nuclear Wave Packets In Pump-Probe Studies Of O₂ With Ultrashort Laser Pulses, S. Xue, H. Du, B. Hu, C. D. Lin, Anh-Thu Le
Following Coherent Multichannel Nuclear Wave Packets In Pump-Probe Studies Of O₂ With Ultrashort Laser Pulses, S. Xue, H. Du, B. Hu, C. D. Lin, Anh-Thu Le
Physics Faculty Research & Creative Works
We reexamine the recent pump-probe experiment with O₂ using short intense infrared laser pulses theoretically. Using parameters that closely mimic the experimental conditions and taking into account the angle-dependent population redistribution due to resonant coupling between the relevant states, we show that the observed kinetic energy release spectra, including the energy-dependent structure and the quantum beat frequencies, can be accurately reproduced. Our results reveal additional important channels that were missed earlier. In particular, the strong contributions from O₂+a4Πu and b4Σb- states lead to the possibility of observing the interchannel beating. We further demonstrate …
All-Optical Atom Trap As A Target For Motrims-Like Collision Experiments, S. Sharma, B. P. Acharya, Daniel Fischer, For Full List Of Authors, See Publisher's Website.
All-Optical Atom Trap As A Target For Motrims-Like Collision Experiments, S. Sharma, B. P. Acharya, Daniel Fischer, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
Momentum-resolved scattering experiments with laser-cooled atomic targets have been performed since almost two decades with magneto-optical trap recoil ion momentum spectroscopy (MOTRIMS) setups. Compared to experiments with gas-jet targets, MOTRIMS features significantly lower target temperatures allowing for an excellent recoil ion momentum resolution. However, the coincident and momentum-resolved detection of electrons was long rendered impossible due to incompatible magnetic field requirements. Here we report on an experimental approach which is based on an all-optical 6Liatom trap that--in contrast to magneto-optical traps--does not require magnetic field gradients in the trapping region. Atom temperatures of about 2 mK and number densities …
Correlation Effects In The Quench-Induced Phase Separation Dynamics Of A Two Species Ultracold Quantum Gas, Simeon I. Mistakidis, Garyfallia C. Katsimiga, P. G. Kevrekidis, P. Schmelcher
Correlation Effects In The Quench-Induced Phase Separation Dynamics Of A Two Species Ultracold Quantum Gas, Simeon I. Mistakidis, Garyfallia C. Katsimiga, P. G. Kevrekidis, P. Schmelcher
Physics Faculty Research & Creative Works
We Explore The Quench Dynamics Of A Binary Bose-Einstein Condensate Crossing The Miscibility-Immiscibility Threshold And Vice Versa, Both Within And In Particular Beyond The Mean-Field Approximation. Increasing The Interspecies Repulsion Leads To The Filamentation Of The Density Of Each Species, Involving Shorter Wavenumbers And Longer Spatial Scales In The Many-Body (MB) Approach. These Filaments Appear To Be Strongly Correlated And Exhibit Domain-Wall Structures. Following The Reverse Quench Process Multiple Dark-Antidark Solitary Waves Are Spontaneously Generated And Subsequently Found To Decay In The MB Scenario. We Simulate Single-Shot Images To Connect Our Findings To Possible Experimental Realizations. Finally, The Growth Rate …
Atomic Physics Constraints On The X Boson, Ulrich D. Jentschura, Istvan Nandori
Atomic Physics Constraints On The X Boson, Ulrich D. Jentschura, Istvan Nandori
Physics Faculty Research & Creative Works
Recently, a peak in the light fermion pair spectrum at invariant q)2 ≈ (16.7MeV)2 has been observed in the bombardment of 7Li by protons. This peak has been interpreted in terms of a protophobic interaction of fermions with a gauge boson (X boson) of invariant mass ≈16.7MeV which couples mainly to neutrons. High-precision atomic physics experiments aimed at observing the protophobic interaction need to separate the X boson effect from the nuclear-size effect, which is a problem because of the short range of the interaction (11.8 fm), which is commensurate with a "nuclear halo." Here we analyze …
Gw170817: Implications For The Stochastic Gravitational-Wave Background From Compact Binary Coalescences, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Gw170817: Implications For The Stochastic Gravitational-Wave Background From Compact Binary Coalescences, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
The LIGO Scientific and Virgo Collaborations have announced the event GW170817, the first detection of gravitational waves from the coalescence of two neutron stars. The merger rate of binary neutron stars estimated from this event suggests that distant, unresolvable binary neutron stars create a significant astrophysical stochastic gravitational-wave background. The binary neutron star component will add to the contribution from binary black holes, increasing the amplitude of the total astrophysical background relative to previous expectations. In the Advanced LIGO-Virgo frequency band most sensitive to stochastic backgrounds (near 25 Hz), we predict a total astrophysical background with amplitude ΩGW( …
Femtosecond Laser Mass Spectrometry And High Harmonic Spectroscopy Of Xylene Isomers, Abdullah Alharbi, Andrewy E. Boguslavskiy, Dane Austin, Nicolas Thire, D. Wood, P. Hawkins, Felicity Mcgrath, A. S. Johnson, I. Lopez-Quintas, Bruno Schmidt, Francois Legare, J. P. Marangos, Anh-Thu Le, Ravi Bhardwaj
Femtosecond Laser Mass Spectrometry And High Harmonic Spectroscopy Of Xylene Isomers, Abdullah Alharbi, Andrewy E. Boguslavskiy, Dane Austin, Nicolas Thire, D. Wood, P. Hawkins, Felicity Mcgrath, A. S. Johnson, I. Lopez-Quintas, Bruno Schmidt, Francois Legare, J. P. Marangos, Anh-Thu Le, Ravi Bhardwaj
Physics Faculty Research & Creative Works
Structural isomers, molecules having the same chemical formula but with atoms bonded in different order, are hard to identify using conventional spectroscopy and mass spectrometry. They exhibit virtually indistinguishable mass spectra when ionized by electrons. Laser mass spectrometry based on photoionization of the isomers has emerged as a promising alternative but requires shaped ultrafast laser pulses. Here we use transform limited femtosecond pulses to distinguish the isomers using two methods. First, we probe doubly charged parent ions with circularly polarized light. We show that the yield of doubly charged ortho-xylene decreases while para-xylene increases over a range of laser intensities …
Fractional Brownian Motion With A Reflecting Wall, Alexander H. O. Wada, Thomas Vojta
Fractional Brownian Motion With A Reflecting Wall, Alexander H. O. Wada, Thomas Vojta
Physics Faculty Research & Creative Works
Fractional Brownian motion, a stochastic process with long-time correlations between its increments, is a prototypical model for anomalous diffusion. We analyze fractional Brownian motion in the presence of a reflecting wall by means of Monte Carlo simulations. Whereas the mean-square displacement of the particle shows the expected anomalous diffusion behavior (x2) ~ tα, the interplay between the geometric confinement and the long-time memory leads to a highly non-Gaussian probability density function with a power-law singularity at the barrier. In the superdiffusive case α > 1, the particles accumulate at the barrier leading to a divergence of the …
First Search For Nontensorial Gravitational Waves From Known Pulsars, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
First Search For Nontensorial Gravitational Waves From Known Pulsars, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper …