Light-Nuclei Spectra From Chiral Dynamics, 2018 Old Dominion University

#### Light-Nuclei Spectra From Chiral Dynamics, M. Piarulli, A. Baroni, L. Girlanda, A. Kievsky, A. Lovato, Ewing Lusk, L. E. Marcucci, Steven C. Pieper, R. Schiavilla, M, Viviani, R. B. Wiringa

*Physics Faculty Publications*

In recent years local chiral interactions have been derived and implemented in quantum Monte Carlo methods in order to test to what extent the chiral effective field theory framework impacts our knowledge of few- and many-body systems. In this Letter, we present Green's function Monte Carlo calculations of light nuclei based on the family of local two-body interactions presented by our group in a previous paper in conjunction with chiral three-body interactions fitted to bound- and scattering-state observables in the three-nucleon sector. These interactions include Δ intermediate states in their two-pion-exchange components. We obtain predictions for the energy levels ...

Subsystem Eigenstate Thermalization Hypothesis, 2018 University of Kentucky

#### Subsystem Eigenstate Thermalization Hypothesis, Anatoly Dymarsky, Nima Lashkari, Hong Liu

*Physics and Astronomy Faculty Publications*

Motivated by the qualitative picture of canonical typicality, we propose a refined formulation of the eigenstate thermalization hypothesis (ETH) for chaotic quantum systems. This formulation, which we refer to as subsystem ETH, is in terms of the reduced density matrix of subsystems. This strong form of ETH outlines the set of observables defined within the subsystem for which it guarantees eigenstate thermalization. We discuss the limits when the size of the subsystem is small or comparable to its complement. In the latter case we outline the way to calculate the leading volume-proportional contribution to the von Neumann and Renyi entanglment ...

Universality Of Fast Quenches From The Conformal Perturbation Theory, 2018 University of Kentucky

#### Universality Of Fast Quenches From The Conformal Perturbation Theory, Anatoly Dymarsky, Michael Smolkin

*Physics and Astronomy Faculty Publications*

We consider global quantum quenches, a protocol when a continuous field theoretic system in the ground state is driven by a homogeneous time-dependent external interaction. When the typical inverse time scale of the interaction is much larger than all relevant scales except for the UV-cutoff the system’s response exhibits universal scaling behavior. We provide both qualitative and quantitative explanations of this universality and argue that physics of the response during and shortly after the quench is governed by the conformal perturbation theory around the UV fixed point. We proceed to calculate the response of one and two-point correlation functions ...

Pentaquarks With Hidden Charm As Hadroquarkonia, 2018 University of Kentucky

#### Pentaquarks With Hidden Charm As Hadroquarkonia, Michael I. Eides, Victor Yu. Petrov, Maxim V. Polyakov

*Physics and Astronomy Faculty Publications*

We consider hidden charm pentaquarks as hadroquarkonium states in a QCD inspired approach. Pentaquarks arise naturally as bound states of quarkonia excitations and ordinary baryons. The LHCb *P _{c}*(4450) pentaquark is interpreted as a

*ψ′*-nucleon bound state with spin-parity

*J*=3/2

^{ P}^{−}. The partial decay width

*Γ*(

*P*(4450) →

_{c}*J*/

*ψ*+

*N*) ≈ 11 MeV is calculated and turned out to be in agreement with the experimental data for

*P*(4450). The

_{c}*P*(4450) pentaquark is predicted to be a member of one of the two almost degenerate hidden-charm baryon octets with spin-parities

_{c}*J*

^{ P ...}Incoherent Qubit Control Using The Quantum Zeno Effect, 2018 University of California, Berkeley

#### Incoherent Qubit Control Using The Quantum Zeno Effect, S. Hachohen-Gourgy, L. P. García-Pintos, L. S. Martin, Justin Dressel, I. Siddiqi

*Mathematics, Physics, and Computer Science Faculty Articles and Research*

The quantum Zeno effect is the suppression of Hamiltonian evolution by repeated observation, which pins the system to an eigenstate of the measurement observable. Using measurement alone, control of the state can be achieved if the observable is slowly varied, so that the state tracks the now time-dependent eigenstate. We demonstrate this using a circuit-QED readout technique that couples to a dynamically controllable observable of a qubit. Continuous monitoring of the measurement record allows us to detect an escape from the eigenstate, thus serving as a built-in form of error detection. We show this by postselecting on realizations with high ...

Scheme For The Protective Measurement Of A Single Photon Using A Tunable Quantum Zeno Effect, 2018 University of Portland

#### Scheme For The Protective Measurement Of A Single Photon Using A Tunable Quantum Zeno Effect, Maximilian Schlosshauer

*Physics Faculty Publications and Presentations*

This paper presents a proof-of-principle scheme for the protective measurement of a single photon. In this scheme, the photon is looped arbitrarily many times through an optical stage that implements a weak measurement of a polarization observable followed by a strong measurement protecting the state. The ability of this scheme to realize a large number of such interaction{protection steps means that the uncertainty in the measurement result can be drastically reduced while maintaining a sufficient probability for the photon to survive the measurement.

A Study Of Neural Networks For The Quantum Many-Body Problem, 2018 Bard College

#### A Study Of Neural Networks For The Quantum Many-Body Problem, Liam B. Schramm

*Senior Projects Spring 2018*

One of the fundamental problems in analytically approaching the quantum many-body problem is that the amount of information needed to describe a quantum state. As the number of particles in a system grows, the amount of information needed for a full description of the system increases exponentially. A great deal of work then has gone into finding efficient approximate representations of these systems. Among the most popular techniques are Tensor Networks and Quantum Monte Carlo methods. However, one new method with a number of promising theoretical guarantees is the Neural Quantum State. This method is an adaptation of the Restricted ...

Widely Tunable On-Chip Microwave Circulator For Superconducting Quantum Circuits, 2018 University of Colorado at Boulder

#### Widely Tunable On-Chip Microwave Circulator For Superconducting Quantum Circuits, Ben J. Chapman

*Physics Graduate Theses & Dissertations*

This thesis develops theory for and experimentally demonstrates a new way to break Lorentz reciprocity—the symmetry, in an electrical network, under exchange of source and detector. The approach is based on the sequential application of frequency conversion and delay; as frequency and time are Fourier duals, these operations do not generally commute. We apply this method in the construction of an on-chip superconducting microwave circulator, a critical component for the unidirectional routing of quantum information in superconducting networks. The device requires neither permanent magnets nor microwave control tones, allowing on-chip integration with other superconducting circuits without expensive control hardware ...

Aspects Of Topology In Quantum Phases Of Matter: A Journey Through Lands Both Flat And Not, 2018 University of Colorado at Boulder

#### Aspects Of Topology In Quantum Phases Of Matter: A Journey Through Lands Both Flat And Not, Abhinav Prem

*Physics Graduate Theses & Dissertations*

Topological quantum phases of matter are often characterized by the presence of fractionalized quasiparticles, which exhibit non-trivial braiding statistics or carry fractional quantum numbers, or of protected gapless surface states. In this thesis, we study topological phases in two and three spatial dimensions, from the perspective of searching for new exotic quantum phases and of characterizing their experimental signatures.

We first study topological defects in fermionic paired superfluids and discover that in the presence of a multiply quantized vortex, such a state hosts unpaired fermions in the BCS regime. We predict that these unpaired fermions will result in an experimentally ...

Strongly Interacting Fermi Gases: Hydrodynamics And Beyond, 2018 University of Colorado at Boulder

#### Strongly Interacting Fermi Gases: Hydrodynamics And Beyond, William E. Lewis

*Physics Graduate Theses & Dissertations*

This thesis considers out-of-equilibrium dynamics of strongly interacting non-relativistic Fermi gases in several two and three dimensional geometries. The tools of second-order hydrodynamics and gauge-gravity duality will be utilized to address this system. Many of the themes of this work are motivated by the observed similarities in transport properties between strongly interacting Fermi gases and other very different strongly interacting quantum fluids such as the quark-gluon plasma, high temperature superconductors, and quantum field theories described by gauge-gravity duality. In particular, these systems all nearly saturate the conjectured lower bound on the ratio of shear viscosity to entropy density *η*/*s ...*

Heisenberg Codes And Channels, 2018 University of Colorado at Boulder

#### Heisenberg Codes And Channels, Sion Nicolas Ledbetter

*Mathematics Graduate Theses & Dissertations*

We construct a classical code, called a *Heisenberg code*, which is not uniquely decipherable in order to mimic the quantum behavior of uncertainty. We classify this code according to two properties and determine the possible codeword lengths for a Heisenberg code. We suggest a possible example of a physical system which utilizes Heisenberg codes. We define a channel for Heisenberg codes, called a *Heisenberg channel*, which is a composite of a *sender state* and a *receiver state* which are matrices of probability amplitudes. We demonstrate that Heisenberg channels have partial trace properties similar to density matrices for quantum states. Next ...

Single Atom Delivery Into A Bottle Beam Trap Using An Optical Conveyor Belt And Quantum Coherent Gain In A Matterwave Transistor, 2018 University of Colorado at Boulder

#### Single Atom Delivery Into A Bottle Beam Trap Using An Optical Conveyor Belt And Quantum Coherent Gain In A Matterwave Transistor, Brad Anthony Dinardo

*Physics Graduate Theses & Dissertations*

The work of this dissertation falls into two broad categories. In the first part, I describe loading a single atom from a reservoir into a blue-detuned crossed vortex bottle beam trap using a dynamic 1D optical lattice. The lattice beams are frequency chirped using acousto-optic modulators, which causes the lattice to move along its axial direction and behave like an optical conveyor belt. A stationary lattice is initially loaded with approximately 6000 atoms from a reservoir, and the conveyor belt transports them 1.1 mm from the reservoir to a bottle beam trap, where a single atom is loaded via ...

Emergent Phenomena In Quantum Critical Systems, 2018 University of Massachusetts Amherst

#### Emergent Phenomena In Quantum Critical Systems, Kun Chen

*Doctoral Dissertations*

A quantum critical point (QCP) is a point in the phase diagram of quantum matter where a continuous phase transition takes place at zero temperature. Low-dimensional quantum critical systems are strongly correlated, therefore hosting nontrivial emergent phenomena. In this thesis, we first address two decades-old problems on quantum critical dynamics. We then reveal two novel emergent phenomena of quantum critical impurity problems. In the first part of the thesis, we address the linear response dynamics of the $(2+1)$-dimensional $O(2)$ quantum critical universality class, which can be realized in the ultracold bosonic system near the superfluid (SF) to ...

Magnetic Field Design To Reduce Systematic Effects In Neutron Electric Dipole Moment Measurements, 2018 University of Kentucky

#### Magnetic Field Design To Reduce Systematic Effects In Neutron Electric Dipole Moment Measurements, James Ryan Dadisman

*Theses and Dissertations--Physics and Astronomy*

Charge-Conjugation (C) and Charge-Conjugation-Parity (CP) Violation is one of the three Sakharov conditions to explain via baryogenesis the observed baryon asymmetry of the universe (BAU). The Standard Model of particle physics (SM) contains sources of CP violation, but cannot explain the BAU. This motivates searches for new physics beyond the standard model (BSM) which address the Sakharov criteria, including high-precision searches for new sources of CPV in systems for which the SM contribution is small, but larger effects may be present in BSM theories. A promising example is the search for the electric dipole moment of the neutron (nEDM), which ...

Time To Stop Telling Biophysics Students That Light Is Primarily A Wave, 2018 University of Pennsylvania

#### Time To Stop Telling Biophysics Students That Light Is Primarily A Wave, Philip C. Nelson

*Department of Physics Papers*

Standard pedagogy introduces optics as though it were a consequence of Maxwell’s equations, and only grudgingly admits, usually in a rushed aside, that light has a particulate character that can somehow be reconciled with the wave picture. Recent revolutionary advances in optical imaging, however, make this approach more and more unhelpful: How are we to describe two-photon imaging, FRET, localization microscopy, and a host of related techniques to students who think of light primarily as a wave? I was surprised to find that everything I wanted my biophysics students to know about light, including image formation, x-ray diffraction, and ...

Selection Rules And Population Trapping In Rydberg States In Strong Field Interactions, 2018 University of Colorado, Boulder

#### Selection Rules And Population Trapping In Rydberg States In Strong Field Interactions, Zetong Xue

*Undergraduate Honors Theses*

We study the excitation to Rydberg states in the interaction of the hydrogen and helium atom with a short strong laser pulse, as it has been analyzed before for monochromatic cw lasers. Utilizing solutions of the time-dependent Schrödinger equation we have analyzed if the parity of the populated angular momentum states agrees with the selection rules for multiphoton resonant absorption. We have further investigated how the results and conclusions depend on the parameters of the laser pulse, such as intensity and pulse length. Different mechanisms to explain the distributions in the populations of the angular momentum states are tested by ...

Scattering Processes And Resonances From Lattice Qcd, 2018 Old Dominion University

#### Scattering Processes And Resonances From Lattice Qcd, Raúl A. Briceño, Jozef J. Dudek, Ross D. Young

*Physics Faculty Publications*

The vast majority of hadrons observed in nature are not stable under the strong interaction; rather they are resonances whose existence is deduced from enhancements in the energy dependence of scattering amplitudes. The study of hadron resonances offers a window into the workings of quantum chromodynamics (QCD) in the low-energy nonperturbative region, and in addition many probes of the limits of the electroweak sector of the standard model consider processes which feature hadron resonances. From a theoretical standpoint, this is a challenging field: the same dynamics that binds quarks and gluons into hadron resonances also controls their decay into lighter ...

Nonadiabatic Multielectron Dynamics In Interaction Of Molecules With Intense Laser Pulses, 2018 University of Colorado at Boulder

#### Nonadiabatic Multielectron Dynamics In Interaction Of Molecules With Intense Laser Pulses, Andres F. Mora

*Undergraduate Honors Theses*

Ultrashort high intensity laser pulses have allowed for the observation of ultrafast dynamics in atoms and molecules. Due to the complexity, these multielectron systems interacting with ultrashort intense laser fields are often theoretically studied using the single active electron approximation (SAE). We present here results of simulations within Time Dependent Density Functional Theory which address the multielectron nature of the studied systems. The results exhibit multielectron effects in form of orbital coupling and non-adiabatic electron dynamics in electron localization, high harmonic generation and ionization of N+ 2 interacting with a strong laser pulse.

Resonances From Lattice Qcd, 2018 Old Dominion University

#### Resonances From Lattice Qcd, Raúl A. Briceño

*Physics Faculty Publications*

The spectrum of hadron is mainly composed as shortly-lived states (resonance) that decay onto two or more hadrons. These resonances play an important role in a variety of phenomenologically significant processes. In this talk, I give an overview on the present status of a rigorous program for studying of resonances and their properties using lattice QCD. I explain the formalism needed for extracting resonant amplitudes from the finite-volume spectra. From these one can extract the masses and widths of resonances. I present some recent examples that illustrate the power of these ideas. I then explain similar formalism that allows for ...

Isoscalar Ππ; Kk; Ηη Scattering And The Σ; F0; F2 Mesons From Qcd, 2018 Old Dominion University

#### Isoscalar Ππ; Kk; Ηη Scattering And The Σ; F0; F2 Mesons From Qcd, Raul A. Briceño, Jozef J. Dudek, Robert G. Edwards, David J. Wilson

*Physics Faculty Publications*

We present the first lattice QCD study of coupled isoscalar *ππ*;K ¯K; *ηη* S- and D-wave scattering extracted from discrete finite-volume spectra computed on lattices which have a value of the light quark mass corresponding to m_{π} ∼ 391 MeV. In the J^{P} = 0^{+} sector we find analogues of the experimental σ and f_{0 }(980) states, where the σ appears as a stable bound-state below *ππ* threshold, and, similar to what is seen in experiment, the f_{0 }(980) manifests itself as a dip in the* ππ* cross section in the vicinity of the K ¯K threshold ...