A5085069729- Cold Atom Physics and Bose-Einstein Condensates
- Nuclear physics research studies
- Physics of Superconductivity and Magnetism
- Quantum Chromodynamics and Particle Interactions
- Quantum, superfluid, helium dynamics
- Advanced NMR Techniques and Applications
- Advanced Chemical Physics Studies
- Quantum Computing Algorithms and Architecture
- Atomic and Subatomic Physics Research
- Quantum Information and Cryptography
- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Theoretical and Computational Physics
- Neural Networks and Reservoir Computing
- Optical properties and cooling technologies in crystalline materials
- Advanced Frequency and Time Standards
- Spectral Theory in Mathematical Physics
- Astronomical and nuclear sciences
- Pickering emulsions and particle stabilization
- Methane Hydrates and Related Phenomena
- Atomic and Molecular Physics
- Strong Light-Matter Interactions
- Quantum and electron transport phenomena
- Elasticity and Wave Propagation
- High-pressure geophysics and materials
University of Washington
2016-2021
Central Washington University
2019-2020
Yale University
2012-2016
University of California, Irvine
2006
We describe and benchmark a new quantum charge-coupled device (QCCD) trapped-ion computer based on linear trap with periodic boundary conditions, which resembles race track. The system successfully incorporates several technologies crucial to future scalability—including electrode broadcasting, multilayer rf routing, magneto-optical (MOT) loading—while maintaining, in some cases exceeding, the gate fidelities of previous QCCD systems. is initially operated 32 qubits, but upgrades will allow...
We describe and benchmark a new quantum charge-coupled device (QCCD) trapped-ion computer based on linear trap with periodic boundary conditions, which resembles race track. The system successfully incorporates several technologies crucial to future scalability, including electrode broadcasting, multi-layer RF routing, magneto-optical (MOT) loading, while maintaining, in some cases exceeding, the gate fidelities of previous QCCD systems. is initially operated 32 qubits, but upgrades will...
The temperature dependence of the contact in unitary Fermi gas is calculated across superfluid phase transition, giving results excellent agreement with most recent precision ultracold atomic experiments.
In the two-component Fermi gas with a contact interaction, pseudogap regime can exist at temperatures between superfluid critical temperature T_{c} and T^{*}>T_{c}. This is characterized by pairing correlations without superfluidity. However, in unitary limit of infinite scattering length, existence this still debated. To help address this, we have applied finite-temperature auxiliary-field quantum Monte Carlo (AFMC) methods to study thermodynamics phase transition signatures spin-balanced...
For sufficiently slow rates of strain, flowing foam can exhibit inhomogeneous flows. The nature these flows is an area active study in both two-dimensional model foams and three dimensional foam. Recent work three-dimensional has identified distinct regimes flow [S. Rodts, J. C. Baudez, P. Coussot, Europhys. Lett. 69, 636 (2005)]. Two are with continuum behavior (full shear banding), the third regime as a discrete exhibiting extreme localization. In this paper, studied more detail using...
We assess the accuracy of finite-temperature mean-field theory using as a standard Hamiltonian and model space shell Monte Carlo calculations. Two examples are considered: nucleus $^{162}$Dy, representing heavy deformed nucleus, $^{148}$Sm, nearby spherical with strong pairing correlations. The errors inherent in Hartree-Fock Hartree-Fock-Bogoliubov approximations analyzed by comparing entropies grand canonical ensembles, well level density at neutron resonance threshold, (SMMC)...
Deformation, a key concept in our understanding of heavy nuclei, is based on mean-field description that breaks the rotational invariance nuclear many-body Hamiltonian. We present method to analyze deformations at finite temperature framework preserves invariance. The auxiliary-field Monte Carlo used generate statistical ensemble and calculate probability distribution associated with quadrupole operator. Applying technique nuclei rare-earth region, we identify model-independent signatures...
The dependence of the nuclear level density on intrinsic deformation is an important input to dynamical processes such as fission. Auxiliary-field Monte Carlo (AFMC) method a powerful for computing densities. However, statistical distribution shapes not readily accessible due formulation AFMC in spherical configuration-interaction shell-model approach. Instead, theory up now has largely relied mean-field approximation which breaks rotational symmetry. We show here how distributions...
Empirical evidence for a gap between the computational powers of classical and quantum computers has been provided by experiments that sample output distributions two-dimensional circuits. Many attempts to close this have utilized simulations based on tensor network techniques, their limitations shed light improvements hardware required frustrate simulability. In particular, having in excess $\sim 50$ qubits are primarily vulnerable simulation due restrictions gate fidelity connectivity,...
Superfluidity in the cold atomic two-species Fermi gas system unitary limit of infinite scattering length remains incompletely understood. In particular, a pseudogap phase has been proposed to exist above superfluid critical temperature. Here we apply auxiliary-field quantum Monte Carlo method perform first ab initio calculations temperature dependence three quantities -- energy-staggering pairing gap, condensate fraction and heat capacity trapped finite-size atom system. As gap require use...
We develop a formalism for calculating the distribution of axial quadrupole operator in laboratory frame within rotationally invariant framework configuration-interaction shell model. The calculation is carried out using finite-temperature auxiliary-field quantum Monte Carlo method. apply this to isotope chains even-mass samarium and neodymium nuclei show that provides model-independent signature nuclear deformation. Two technical advances are described greatly facilitate calculations. first...
We extend a recently introduced separable interaction for the unitary trapped Fermi gas to all values of scattering length. derive closed expressions matrix elements and two-particle eigenvectors. At unitarity we analytically demonstrate convergence this zero-range two-body pseudopotential $s$-wave scattering. apply effective three- four-particle systems along BEC-BCS crossover find that their low-lying energies exhibit in regularization parameter is much faster than conventional...
Conventional diagonalization methods to calculate nuclear energy levels in the framework of configuration-interaction (CI) shell model approach are prohibited very large spaces. The Monte Carlo (SMMC) is a powerful technique for calculating thermal and ground-state observables nuclei spaces, but it challenging extract spectra this approach. We present novel method low-lying given values set good quantum numbers such as spin parity. based on imaginary-time one-body density correlation...
The unitary Fermi gas (UFG) is a strongly correlated system of two-species (spin-1/2) fermions with short-range attractive interaction modeled by contact and has attracted much interest across different disciplines. UFG considered paradigm for superfluids been investigated extensively, generally good agreement found between theory experiment. However, the extent pseudogap regime above critical temperature $T_c$ superfluidity still debated both theoretically experimentally. Here we study...
Nuclear energy levels are usually calculated using conventional diagonalization methods in the framework of configuration-interaction (CI) shell model but these prohibited very large spaces. The Monte Carlo (SMMC) method is a powerful technique for calculating thermal and ground-state observables nuclei spaces, it challenging to extract nuclear spectra this approach. We present novel within SMMC low-lying given values set good quantum numbers such as spin parity. based on imaginary-time...
Laser cooling methods for trapped ions are most commonly studied at low energies, i.e., in the Lamb-Dicke regime. However, experiments often excited to higher energies which approximation breaks down. Here we construct a non-perturbative, semiclassical method predicting energy-dependent dynamics of trapped-ion crystals with potentially many internal levels and motional modes beyond This allows accurate efficient modeling variety interesting phenomena, such as breakdown EIT high simultaneous...
The auxiliary-field quantum Monte Carlo (AFMC) method is a powerful and widely used technique for ground-state finite-temperature simulations of many-body systems. We introduce several algorithmic improvements AFMC calculations dilute fermionic systems that reduce the computational complexity most parts algorithm. This principally achieved by reducing number single-particle states contribute at each configuration auxiliary fields to order fermions. Our methods are applicable both canonical...
We review a method that we recently introduced to calculate the finite-temperature distribution of axial quadrupole operator in laboratory frame using auxiliary-field Monte Carlo technique framework configuration-interaction shell model. also discuss recent work determine probability shape tensor as function intrinsic deformation β,γ by expanding its logarithm invariants. demonstrate our for an isotope chain samarium nuclei whose ground states describe crossover from spherical deformed shapes.
We introduce a new scheme for quantum circuit design called controlled gate networks. Rather than trying to reduce the complexity of individual unitary operations, objective networks is toggle between all operations needed with fewest number gates. illustrate our approach using specific class networks, reversal gates, estimate eigenvalues two-qubit Hamiltonian via Rodeo Algorithm. A five-fold reduction in gates observed as compared an equivalent standard use Quantinuum H1-2 and IBM Perth...
Nuclear level densities are necessary input to the Hauser-Feshbach theory of compound nuclear reactions. However, microscopic calculation in presence correlations is a challenging many-body problem. The configurationinteraction shell model provides suitable framework for inclusion and effects, but large dimensionality many-particle space has limited its application heavy nuclei. Monte Carlo method enables calculations spaces that many orders magnitude larger than can be treated by...