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Biomedical subjects

S H Simon

Publications and source records attributed to S H Simon.

13 recordsLinked to original sources
PubMed2006

Topological quantum computing with only one mobile quasiparticle.

In a topological quantum computer, universal quantum computation is performed by dragging quasiparticle excitations of certain two dimensional systems around each other to form braids of their world lines in 2 + 1 dimensional space-time. In this Letter we show that any such quantum computation that can be done by braiding n identical quasiparticles can also be done by moving a single quasiparticle around n - 1 other identical quasiparticles whose positions remain fixed.

Journal Article↗
PubMed2005

Vortex lattices in rotating atomic bose gases with dipolar interactions.

We show that dipolar interactions have dramatic effects on the ground states of rotating atomic Bose gases in the weak-interaction limit. With increasing dipolar interaction (relative to the net contact interaction), the mean field, or high filling factor, ground state undergoes a series of transitions between vortex lattices of different symmetries: triangular, square, "stripe," and "bubble" phases. We also study the effects of dipolar interactions on the quantum fluids at low filling factors. We show that the incompressible Laughlin state at filling factor nu = 1/2 is replaced by compressible stripe and bubble phases.

Journal Article↗
PubMed2005

Braid topologies for quantum computation.

In topological quantum computation, quantum information is stored in states which are intrinsically protected from decoherence, and quantum gates are carried out by dragging particlelike excitations (quasiparticles) around one another in two space dimensions. The resulting quasiparticle trajectories define world lines in three-dimensional space-time, and the corresponding quantum gates depend only on the topology of the braids formed by these world lines. We show how to find braids that yield a universal set of quantum gates for qubits encoded using a specific kind of quasiparticle which is particularly promising for experimental realization.

Journal Article↗
PubMed2001

Oscillating sign of drag in high Landau levels.

Motivated by experiments, we study the sign of the Coulomb drag voltage in a double layer system in a strong magnetic field. We show that the commonly used Fermi golden rule approach implicitly assumes a linear dependence of intralayer conductivity on density, and is thus inadequate in strong magnetic fields. Going beyond this approach, we show that the drag voltage commonly changes sign with density difference between the layers. We find that, in the quantum Hall regime, the Hall and longitudinal drag resistivities may be comparable. Our results are also relevant for pumping and acoustoelectric experiments.

Journal Article↗
PubMed1979

Negative effects of oral fatty acid supplementation on sweat chloride in cystic fibrosis.

Essential fatty acid supplementation with oral safflower oil (1 gm/kg/day) to 11 cystic fibrosis patients (aged 6 months to 14 years) for one year produced no significant change in sweat chloride concentration (mEq/liter) or sweat rate (gm/min/m2), Addition of vitamin E (10 mg/kg/day) to the safflower oil had no effect on sweat chloride concentration or rate compared to placebo. No clinical improvement could be detected compared to a control group. These results do not support previous reports of the effects of fatty acid supplementation on sweat electrolyte concentrations in cystic fibrosis.

Adolescent↗
PubMedDate not supplied

The HRIS: what capabilities must it have?

Unfortunately, there are no commonly accepted standards to guide personnel managers in evaluating HRIS (human resources information system) software. Until such standards developed, the advice offered here by author Sidney H. Simon (manager of personnel information systems and benefits administration of Bechtel Power Corporation) will stand the personnel manager in good stead. Focusing on the minimum capabilities that any HRIS should possess, he discusses the basic functions of input, data maintenance, and output in terms of both standard and optional items. This is not to say, however, that the personnel manager need do no homework. Simon emphasizes the importance having carefully and accurately defined the data required to support a company's personnel functions before software evaluation even begins. And he notes that human resources managers will have to familiarize themselves with some of the data processing terminology in use, just as the data processors have to familiarize themselves with personnel terminology. Simon illustrates the text with eight exhibits that clarify the functions explained to help the reader translate the concepts involved in terms of his or her organization's needs.

Computers↗