59/11/20 Report re: Richard Eberling polygraph test

Report regarding Richard Eberling\u27s polygraph test on 11/19/1959

A Study of Counselor\u27s Legal Challenges and Their Perceptions of Their Ability to Respond

The authors explore the results of a study that assessed the types and frequency of legal issues encountered by counselors and counselors’ perceptions of their ability to respond to these issues. They also assessed whether the participants’ perceptions were related to practice setting, years of experience, completion of a course in ethics, recent completion of continuing education in ethics or legal issues, state licensure status, certification by the National Board of Certified Counselors (NBCC), and highest degree earned. Results demonstrate that counselors feel most prepared to deal with situations encountered most often, but that school counselors do not feel as prepared to face most ethical and legal issues

Inelastic tunneling in a double quantum dot coupled to a bosonic environment

Coupling a quantum system to a bosonic environment always give rise to inelastic processes, which reduce the coherency of the system. We measure energy dependent rates for inelastic tunneling processes in a fully controllable two-level system of a double quantum dot. The emission and absorption rates are well repro-duced by Einstein's coefficients, which relate to the spontaneous emission rate. The inelastic tunneling rate can be comparable to the elastic tunneling rate if the boson occupation number becomes large. In the specific semiconductor double dot, the energy dependence of the inelastic rate suggests that acoustic phonons are coupled to the double dot piezoelectrically.Comment: 6 pages, 4 figure

Random phases in Bose-Einstein condensates with higher order nonlinearities

We present a statistical description of Bose-Einstein condensates with general higher order nonlinearities. In particular, we investigate the case of cubic-quintic nonlinearities, of particular interest for dilute condensates. The implication of decoherence for the stability properties of the condensate is discussed.Comment: 3 pages, no figs., to appear in Eur. Phys. J.

Many Body Correlation Corrections to Superconducting Pairing in Two Dimensions.

We demonstrate that in the strong coupling limit (the superconducting gap $\Delta$ is as large as the chemical potential $\mu$), which is relevant to the high-$T_c$ superconductivity, the correlation corrections to the gap and critical temperature are about 10\% of the corresponding mean field approximation values. For the weak coupling ($\Delta \ll \mu$) the correlation corrections are very large: of the order of 100\% of the corresponding mean field values.Comment: LaTeX 12 page

Canonically conjugate pairs and phase operators

For quantum mechanics on a lattice the position (``particle number'') operator and the quasi-momentum (``phase'') operator obey canonical commutation relations (CCR) only on a dense set of the Hilbert space. We compare exact numerical results for a particle in simple potentials on the lattice with the expectations, when the CCR are assumed to be strictly obeyed. Only for sufficiently smooth eigenfunctions this leads to reasonable results. In the long time limit the use of the CCR can lead to a qualitativel wrong dynamics even if the initial state is in the dense set.Comment: 4 pages, 5 figures. Phys. Rev. A, in pres

Dissipative dynamics in a quantum register

A model for a quantum register dissipatively coupled with a bosonic thermal bath is studied. The register consists of $N$ qubits (i.e. spin ${1/2}$ degrees of freedom), the bath is described by $N_b$ bosonic modes. The register-bath coupling is chosen in such a way that the total number of excitations is conserved. The Hilbert space splits allowing the study of the dynamics separately in each sector. Assuming that the coupling with the bath is the same for all qubits, the excitation sectors have a further decomposition according the irreducible representations of the $su(2)$ spin algebra. The stability against environment-generated noise of the information encoded in a quantum state of the register depends on its $su(2)$ symmetry content. At zero temperature we find that states belonging to the vacuum symmetry sector have for long time vanishing fidelity, whereas each lowest spin vector is decoupled from the bath and therefore is decoherence free. Numerical results are shown in the one-excitation space in the case qubit-dependent bath-system coupling.Comment: to appear on Phys. Rev. A, 8 pages + 5 postscript figure

Interference of Bose-Einstein condensates in momentum space

We suggest an experiment to investigate the linear superposition of two spatially separated Bose-Einstein condensates. Due to the coherent combination of the two wave functions, the dynamic structure factor, measurable through inelastic photon scattering at high momentum transfer $q$, is predicted to exhibit interference fringes with frequency period $\Delta\nu = q/md$ where $d$ is the distance between the condensates. We show that the coherent configuration corresponds to an eigenstate of the physical observable measured in the experiment and that the relative phase of the condensates is hence created through the measurement process.Comment: 4 pages and 2 eps figure

Nuclear Spin Qubit Dephasing Time in the Integer Quantum Hall Effect Regime

We report the first theoretical estimate of the nuclear-spin dephasing time T_2 owing to the spin interaction with the two-dimensional electron gas, when the latter is in the integer quantum Hall state, in a two-dimensional heterojunction or quantum well at low temperature and in large applied magnetic field. We establish that the leading mechanism of dephasing is due to the impurity potentials that influence the dynamics of the spin via virtual magnetic spin-exciton scattering. Implications of our results for implementation of nuclear spins as quantum bits (qubits) for quantum computing are discussed.Comment: 19 pages in plain Te

Strong-coupling expansion for the Hubbard model in arbitrary dimension using slave bosons

A strong-coupling expansion for the antiferromagnetic phase of the Hubbard model is derived in the framework of the slave-boson mean-field approximation. The expansion can be obtained in terms of moments of the density of states of freely hopping electrons on a lattice, which in turn are obtained for hypercubic lattices in arbitrary dimension. The expansion is given for the case of half-filling and for the energy up to fifth order in the ratio of hopping integral $t$ over on-site interaction $U$, but can straightforwardly be generalized to the non-half-filled case and be extended to higher orders in $t/U$. For the energy the expansion is found to have an accuracy of better than $1 \%$ for $U/t \geq 8$. A comparison is given with an earlier perturbation expansion based on the Linear Spin Wave approximation and with a similar expansion based on the Hartree-Fock approximation. The case of an infinite number of spatial dimensions is discussed.Comment: 12 pages, LaTeX2e, to be published in Phys. Rev.