Book Reviews

Review of Prehistory, by Derek Roe; Aspects of Prehistory, by Grahame Clark; World Prehistory, by Grahame Clark; Introductory Readings in Archaeology, by Brian M. Fagan, ed.; The Origins of Civilization, by Carroll L. Riley; The Archaeology of Early Man, by J. M. Coles and E. S. Higgs; Shipwrecks and Archaeology, by Peter Throckmorton; A History of Dyed Textiles, by Stuart Robinson; Food in Antiquity, by Don and Patricia Brothwell; World Archaeology, Vol. 1, nos. 1, 2, 3, by Roy Hodson and Colin Platt, eds.; The Structure and Growth of Australia's Aboriginal Population, by F. Lancaster Jones; Attitudes and Social Conditions, by Ronald Taft, John L. M. Dawson, and Pamela Beasley; Aboriginal Settlements, by J. P. M. Long; The Destruction of Aboriginal Society, by C. D. Rowley; Aboriginal Advancement to Integration, by H. P. Schapper

Coupled Bose-Einstein condensate: Collapse for attractive interaction

We study the collapse in a coupled Bose-Einstein condensate of two types of bosons 1 and 2 under the action of a trap using the time-dependent Gross-Pitaevskii equation. The system may undergo collapse when one, two or three of the scattering lengths $a_{ij}$ for scattering of boson $i$ with $j$, $i,j = 1, 2$, are negative representing an attractive interaction. Depending on the parameters of the problem a single or both components of the condensate may experience collapse.Comment: 5 pages and 9 figures, small changes mad

Toward scalable quantum computation with cavity QED systems

We propose a scheme for quantum computing using high-Q cavities in which the qubits are represented by single cavity modes restricted in the space spanned by the two lowest Fock states. We show that single qubit operations and universal multiple qubit gates can be implemented using atoms sequentially crossing the cavities.Comment: 14 pages, 8 figure

Dynamics of evaporative cooling in magnetically trapped atomic hydrogen

We study the evaporative cooling of magnetically trapped atomic hydrogen on the basis of the kinetic theory of a Bose gas. The dynamics of trapped atoms is described by the coupled differential equations, considering both the evaporation and dipolar spin relaxation processes. The numerical time-evolution calculations quantitatively agree with the recent experiment of Bose-Einstein condensation with atomic hydrogen. It is demonstrated that the balance between evaporative cooling and heating due to dipolar relaxation limits the number of condensates to 9x10^8 and the corresponding condensate fraction to a small value of 4% as observed experimentally.Comment: 5 pages, REVTeX, 3 eps figures, Phys. Rev. A in pres

Simple method for excitation of a Bose-Einstein condensate

An appropriate, time-dependent modification of the trapping potential may be sufficient to create effectively collective excitations in a cold atom Bose-Einstein condensate. The proposed method is complementary to earlier suggestions and should allow the creation of both dark solitons and vortices.Comment: 8 pages, 7 figures, version accepted for publication in Phys. Rev.

Split-merge cycle, fragmented collapse, and vortex disintegration in rotating Bose-Einstein condensates with attractive interactions

The dynamical instabilities and ensuing dynamics of singly- and doubly-quantized vortex states of Bose-Einstein condensates with attractive interactions are investigated using full 3D numerical simulations of the Gross-Pitaevskii equation. With increasing the strength of attractive interactions, a series of dynamical instabilities such as quadrupole, dipole, octupole, and monopole instabilities emerge. The most prominent instability depends on the strength of interactions, the geometry of the trapping potential, and deviations from the axisymmetry due to external perturbations. Singly-quantized vortices split into two clusters and subsequently undergo split-merge cycles in a pancake-shaped trap, whereas the split fragments immediately collapse in a spherical trap. Doubly-quantized vortices are always unstable to disintegration of the vortex core. If we suddenly change the strength of interaction to within a certain range, the vortex splits into three clusters, and one of the clusters collapses after a few split-merge cycles. The vortex split can be observed using a current experimental setup of the MIT group.Comment: 11 pages, 10 figure

Generation of entangled states of two atoms inside a leaky cavity

An in-depth theoretical study is carried out to examine the quasi-deterministic entanglement of two atoms inside a leaky cavity. Two $\Lambda$-type three-level atoms, initially in their ground states, may become maximally entangled through the interaction with a single photon. By working out an exact analytic solution, we show that the probability of success depends crucially on the spectral function of the injected photon. With a cavity photon, one can generate a maximally entangled state with a certain probability that is always less than 50%. However, for an injected photon with a narrower spectral width, this probability can be significantly increased. In particular, we discover situations in which entanglement can be achieved in a single trial with an almost unit probability

A developmental analysis of communication between mothers and infants with Down's syndrome

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68850/2/10.1177_027112148300300110.pd

Many particle entanglement in two-component Bose-Einstein Condensates

We investigate schemes to dynamically create many particle entangled states of a two component Bose-Einstein condensate in a very short time proportional to 1/N where $N$ is the number of condensate particles. For small $N$ we compare exact numerical calculations with analytical semiclassical estimates and find very good agreement for $N \geq 50$. We also estimate the effect of decoherence on our scheme, study possible scenarios for measuring the entangled states, and investigate experimental imperfections.Comment: 12 pages, 8 figure

Three-body halos. V. Computations of continuum spectra for Borromean nuclei

We solve the coordinate space Faddeev equations in the continuum. We employ hyperspherical coordinates and provide analytical expressions allowing easy computation of the effective potentials at distances much larger than the ranges of the interactions where only s-waves in the different Jacobi coordinates couple. Realistic computations are carried out for the Borromean halo nuclei 6He (n+n+\alpha) for J\pi = 0+-, 1+-, 2+- and 11Li (n+n+9Li) for (1/2)+-, (3/2)+-, (5/2)+-. Ground state properties, strength functions, Coulomb dissociation cross sections, phase shifts, complex S-matrix poles are computed and compared to available experimental data. We find enhancements of the strength functions at low energies and a number of low-lying S-matrix poles.Comment: 35 pages, 14 figure