Información del autor
Autor Creffield, Charles E. |
Documentos disponibles escritos por este autor (46)
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We investigate the dynamics of two interacting electrons confined to a pair of coupled quantum dots driven by an external ac field. By numerically integrating the two-electron Schrödinger equation in time, we find that for certain values of the [...]![]()
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Hur, G. ; Creffield, Charles E. ; Jones, P.H. ; Monteiro, T. S. | American Physical Society | 2005-07Recently, cesium atoms in optical lattices subjected to cycles of unequally spaced pulses have been found to show interesting behavior: they represent an experimental demonstration of a Hamiltonian ratchet mechanism, and they show strong variabi[...]![]()
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A powerful method of manipulating the dynamics of quantum coherent particles is to control the phase of their tunneling. We consider a system of two electrons hopping on a quasi-one- dimensional lattice in the presence of a uniform magnetic fiel[...]![]()
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We study the behavior of ultracold bosonic atoms held in an optical lattice. We first show how a self-trapping transition can be induced in the system either by increasing the number of atoms occupying a lattice site or by raising the interactio[...]![]()
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We study the response of a Bose-Einstein condensate to an unbiased periodic driving potential. By controlling the space and time symmetries of the driving we show how a directed current can be induced, producing a coherent quantum ratchet. Weak [...]![]()
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We study the effect of a strong, oscillating driving field on the dynamics of ultracold boson held in an optical lattice. Modeling the system as a Bose-Hubbard model, we show how the driving field can be used to produce and maintain a coherent a[...]![]()
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We consider the dynamics of a quantum particle held in a lattice potential and subjected to a time-dependent spin-orbit coupling. Tilting the lattice causes the particle to perform Bloch oscillations, and by suitably changing the Rashba interact[...]![]()
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We examine the dynamics of ultracold atoms held in optical-lattice potentials. By controlling the switching of a periodic driving potential we show how a phase-induced renormalization of the intersite tunneling can be used to produce directed mo[...]![]()
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The dynamics of cold bosonic atoms held in an optical lattice can be profoundly modified by using a periodic driving potential to induce the quantum interference effect termed ”coherent destruction of tunneling”. In this way the entanglement and[...]![]()
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In the limit of low particle density, electrons confined to a quantum dot form strongly correlated states termed Wigner molecules, in which the Coulomb interaction causes the electrons to become highly localized in space. By using an effective m[...]![]()
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Bose-Einstein condensates subject to short pulses (kicks) from standing waves of light represent a nonlinear analog of the well-known chaos paradigm, the quantum kicked rotor. Previous studies of the onset of dynamical instability (i.e., expo[...]![]()
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Heimsoth, Martin ; Hochstuhl, D. ; Creffield, Charles E. ; Carr, L.D. ; Sols Lucía, Fernando | IOP Publishing | 2013-10-07We show that the orbital Josephson effect appears in a wide range of driven atomic Bose-Einstein condensed systems, including quantum ratchets, double wells and box potentials. We use three separate numerical methods: the Gross-Pitaevskii equati[...]![]()
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A quantum dot (QD) is a structure in which electrons can be confined to small length scales, comparable to their Fermi wavelength. A set of electrons held in such a structure is conceptually similar to a set of atomic electrons bound to a nucleu[...]![]()
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Creffield, Charles E. ; Sols Lucía, Fernando ; Ciampini, D. ; Morsch, O. ; Arimondo, E. | American Physical Society | 2014-01-27We study the nonequilibrium dynamics of cold atoms held in an optical lattice subjected to a periodic driving potential. The expansion of an initially confined atom cloud occurs in two phases: an initial quadratic expansion followed by a ballist[...]![]()
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The Riemann hypothesis, which states that the nontrivial zeros of the Riemann zeta function all lie on a certain line in the complex plane, is one of the most important unresolved problems in mathematics. We propose here an approach to finding a[...]![]()
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Creffield, Charles E. ; Kornilovitch, P. E. ; Klepfish, E. G. ; Pike, E. R. ; Sarkar, Sarben | IOP Publishing Ltd. | 1997-05-05A Quantum Monte Carlo calculation of dynamical spin susceptibility in the half-filled 2D Hubbard model is presented for temperature T = 0.2t and an intermediate on-site repulsion U = 4t. Using the singular value decomposition technique we succee[...]![]()
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We describe a method to generate a synthetic gauge potential for ultracold atoms held in an optical lattice. Our approach uses a time-periodic driving potential based on quickly alternating two Hamiltonians to engineer the appropriate Aharonov-B[...]![]()
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He, Ran ; Ai, Ming-Zhong ; Cui, Jin-Ming ; Huang, Yun-Feng ; Han, Yong-Jian ; Li, Chuan-Feng ; Tu, Tao ; Creffield, Charles E. ; Sierra, G. ; Guo, Guang-Can | Amercican Physical Society | 2020-04-20The Riemann hypothesis, one of the most important open problems in pure mathematics, implies the most profound secret of prime numbers. One of the most interesting approaches to solving this hypothesis is to connect the problem with the spectrum[...]![]()
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We investigate the dynamics of a Bose-Einstein condensate held in an optical lattice under the influence of a strong periodic driving potential. Studying the mean-field version of the Bose- Hubbard model reveals that the condensate becomes dynam[...]![]()
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Creffield, Charles E. ; Háusler, Wolfgang ; Jefferson, John H ; Sarkar, Sarben | American Physical Society | 1999-04-15The low-lying eigenstates of a system of two electrons confined within a two-dimensional quantum dot with a hard polygonal boundary are obtained by means of exact diagonalization. The transition from a weakly correlated charge distribution for s[...]![]()
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The quantum dynamics of atoms subjected to pairs of closely spaced delta kicks from optical potentials are shown to be quite different from the well-known paradigm of quantum chaos, the single delta-kick system. We find the unitary matrix has a [...]![]()
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We investigate the dynamics of two interacting electrons moving in a one-dimensional array of quantum dots under the influence of an ac field. We show that the system exhibits two distinct regimes of behavior, depending on the ratio of the stre[...]