Browsing FAS Scholarly Articles by Keyword "quantum physics"
Now showing items 21-40 of 56
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Long-Distance Spin-Spin Coupling via Floating Gates
(American Physical Society, 2012)The electron spin is a natural two-level system that allows a qubit to be encoded. When localized in a gate-defined quantum dot, the electron spin provides a promising platform for a future functional quantum computer. The ... -
Mapping of Coulomb Gases and Sine-Gordon Models to Statistics of Random Surfaces
(American Physical Society, 2008)We introduce a new class of sine-Gordon models, for which interaction term is present in a region different from the domain over which quadratic part is defined. We develop a novel non-perturbative approach for calculating ... -
Modified Scaled Hierarchical Equation of Motion Approach for the Study of Quantum Coherence in Photosynthetic Complexes
(American Chemical Society, 2011)We present a detailed theoretical study of the transfer of electronic excitation energy through the Fenna−Matthews−Olson (FMO) pigment−protein complex, using the newly developed modified scaled hierarchical approach (Shi, ... -
Non-Markovian Quantum Jumps in Excitonic Energy Transfer
(American Institute of Physics, 2009)We utilize the novel non-Markovian quantum jump (NMQJ) approach to stochastically simulate exciton dynamics derived from a time-convolutionless master equation. For relevant parameters and time scales, the time-dependent, ... -
Nuclear Spin Cooling Using Overhauser-Field Selective Coherent Population Trapping
(American Physical Society, 2010)We show that a quantum interference effect in optical absorption from two electronic spin states of a solid-state emitter can be used to prepare the surrounding environment of nuclear spins in well-defined states, thereby ... -
Photon-Assisted Tunneling in a Biased Strongly Correlated Bose Gas
(American Physical Society, 2011)We study the impact of coherently generated lattice photons on an atomic Mott insulator subjected to a uniform force. Analogous to an array of tunnel-coupled and biased quantum dots, we observe sharp, interaction-shifted ... -
Photon-Photon Interactions via Rydberg Blockade
(American Physical Society, 2011)We develop the theory of light propagation under the conditions of electromagnetically induced transparency in systems involving strongly interacting Rydberg states. Taking into account the quantum nature and the spatial ... -
Photonic Quantum Simulators
(Nature Publishing Group, 2012)Quantum simulators are controllable quantum systems that can be used to mimic other quantum systems. They have the potential to enable the tackling of problems that are intractable on conventional computers. The photonic ... -
Photonic Quantum Transport in a Nonlinear Optical Fiber
(Institute of Physics, 2011)We theoretically study the transmission of few-photon quantum fields through a strongly nonlinear optical medium. We develop a general approach to investigate nonequilibrium quantum transport of bosonic fields through a ... -
Probing Biological Light-Harvesting Phenomena by Optical Cavities
(American Physical Society, 2012)We propose a driven optical cavity quantum electrodynamics (QED) setup aimed at directly probing energy transport dynamics in photosynthetic biomolecules. We show that detailed information concerning energy transfer paths ... -
Probing the Superfluid to Mott Insulator Transition at the Single Atom Level
(American Association for the Advancement of Science, 2010)Quantum gases in optical lattices offer an opportunity to experimentally realize and explore condensed matter models in a clean, tunable system. We used single atom–single lattice site imaging to investigate the Bose-Hubbard ... -
Properties of Nitrogen-Vacancy Centers in Diamond: The Group Theoretic Approach
(Institute of Physics, 2011)We present a procedure that makes use of group theory to analyze and predict the main properties of the negatively charged nitrogen-vacancy (NV) center in diamond. We focus on the relatively low temperature limit where ... -
Quantum Computing Without Wavefunctions: Time-Dependent Density Functional Theory for Universal Quantum Computation
(Nature Publishing Group, 2012)We prove that the theorems of TDDFT can be extended to a class of qubit Hamiltonians that are universal for quantum computation. The theorems of TDDFT applied to universal Hamiltonians imply that single-qubit expectation ... -
Quantum Correlation in Disordered Spin Systems: Applications to Magnetic Sensing
(American Physical Society, 2009)We propose a strategy to generate a many-body entangled state in a collection of randomly placed, dipolarly coupled electronic spins in the solid state. By using coherent control to restrict the evolution into a suitable ... -
Quantum Critical States and Phase Transitions in the Presence of Non-Equilibrium Noise
(Nature Publishing Group, 2010)Quantum critical points are characterized by scale invariant correlations and correspondingly long-ranged entanglement. As such, they present fascinating examples of quantum states of matter, the study of which has been ... -
Quantum Magnetism and Criticality
(Nature Publishing Group, 2008)Magnetic insulators have proved to be fertile ground for studying new types of quantum many body states, and I survey recent experimental and theoretical examples. The insights and methods transfer also to novel superconducting ... -
The Quantum Phases of Matter
(World Scientific Publishing, 2012)I present a selective survey of the phases of quantum matter with varieties of many-particle quantum entanglement. I classify the phases as gapped, conformal, or compressible quantum matter. Gapped quantum matter is ... -
Quantum Process Tomography of Multichromophoric Systems via Ultrafast Spectroscopy
(2011)The description of excited state dynamics in multichromophoric systems constitutes both a theoretical and experimental challenge in modern physical chemistry. An experimental protocol which can systematically characterize ... -
Quantum Simulation of Antiferromagnetic Spin Chains in an Optical Lattice
(Nature Publishing Group, 2011)Understanding exotic forms of magnetism in quantum mechanical systems is a central goal of modern condensed matter physics, with implications for systems ranging from high-temperature superconductors to spintronic devices. ... -
Quantum Transport of Strongly Interacting Photons in a One-Dimensional Nonlinear Waveguide
(American Physical Review, 2012)We present a theoretical technique for solving the quantum transport problem of a few photons through a one-dimensional, strongly nonlinear waveguide. We specifically consider the situation where the evolution of the optical ...