Ellsberg Paradox: Ambiguity And Complexity Aversions Compared

We present a simple model where preferences with complexity aversion, rather than ambiguity aversion, resolve the Ellsberg paradox. We test our theory using laboratory experiments where subjects choose among lotteries that “range” from a simple risky lottery, through risky but more complex lotteries, to one similar to Ellsberg’s ambiguity urn. Our model ranks lotteries according to their complexity and makes different—at times contrasting—predictions than most models of ambiguity in response to manipulations of prizes. The results support that complexity aversion preferences play an important and separate role from beliefs with ambiguity aversion in explaining behavior under uncertainty

Multipartite entanglement of fermionic systems in noninertial frames

The bipartite and tripartite entanglement of a 3-qubit fermionic system when one or two subsystems accelerated are investigated. It is shown that all the one-tangles decrease as the acceleration increases. However, unlike the scalar case, here one-tangles ${\cal N}_{C_I(AB_I)}$ and ${\cal N}_{C_I(AB)}$ never reduce to zero for any acceleration. It is found that the system has only tripartite entanglement when either one or two subsystems accelerated, which means that the acceleration doesn't generate bipartite entanglement and doesn't effect the entanglement structure of the quantum states in this system. It is of interest to note that the $\pi$-tangle of the two-observers-accelerated case decreases much quicker than that of the one-observer-accelerated case and it reduces to a non-zero minimum in the infinite acceleration limit. Thus we argue that the qutrit systems are better than qubit systems to perform quantum information processing tasks in noninertial systems.Comment: 12 pages, 3 figure

Trapping radioactive ^{82}Rb in an optical dipole trap and evidence of spontaneous spin polarization

Optical trapping of selected species of radioactive atoms has great potential in precision measurements for testing fundamental physics such as EDM, PNC and parity violating beta-decay asymmetry correlation coefficients. We report trapping of 10^4 radioactive ^{82}Rb atoms (t_{1/2}=75 s) with a trap lifetime of ~55 seconds in an optical dipole trap. Transfer efficiency from the magneto-optical trap was ~14%. We further report the evidence of spontaneous spin polarization of the atoms in optical dipole trap loading. This advancement is an important step towards a new generation of precision J-beta correlations measurements with polarized ^{82}Rb atoms.Comment: 4 pages, 4 figure

Exotic quantum phase transitions in a Bose-Einstein condensate coupled to an optical cavity

A new extended Dicke model, which includes atom-atom interactions and a driving classical laser field, is established for a Bose-Einstein condensate inside an ultrahigh-finesse optical cavity. A feasible experimental setup with a strong atom-field coupling is proposed, where most parameters are easily controllable and thus the predicted second-order superradiant-normal phase transition may be detected by measuring the ground-state atomic population. More intriguingly, a novel second-order phase transition from the superradiant phase to the \textquotedblleft Mott" phase is also revealed. In addition, a rich and exotic phase diagram is presented.Comment: 4 pages; figures 1 and 3 are modified; topos are correcte

Readout of solid-state charge qubits using a single-electron pump

A major difficulty in realizing a solid-state quantum computer is the reliable measurement of the states of the quantum registers. In this paper, we propose an efficient readout scheme making use of the resonant tunneling of a ballistic electron produced by a single electron pump. We treat the measurement interaction in detail by modeling the full spatial configuration, and show that for pumped electrons with suitably chosen energy the transmission coefficient is very sensitive to the qubit state. We further show that by using a short sequence of pumping events, coupled with a simple feedback control procedure, the qubit can be measured with high accuracy.Comment: 5 pages, revtex4, 4 eps figures. v2: published versio

Spin squeezing in nonlinear spin coherent states

We introduce the nonlinear spin coherent state via its ladder operator formalism and propose a type of nonlinear spin coherent state by the nonlinear time evolution of spin coherent states. By a new version of spectroscopic squeezing criteria we study the spin squeezing in both the spin coherent state and nonlinear spin coherent state. The results show that the spin coherent state is not squeezed in the x, y, and z directions, and the nonlinear spin coherent state may be squeezed in the x and y directions.Comment: 4 pages, 2 figs, revised version submitted to J. Opt.

Energy Dependence of Jet Quenching and Life-time of the Dense Matter in High-energy Heavy-ion Collisions

Suppression of high $p_T$ hadron spectra in high-energy heavy-ion collisions at different energies is studied within a pQCD parton model incorporating medium induced parton energy loss. The $p_T$ dependence of the nuclear modification factor $R_{AA}(p_T)$ is found to depend on both the energy dependence of the parton energy loss and the power-law behavior of the initial jet spectra. The high $p_T$ hadron suppression at $\sqrt{s}=62.4$ GeV and its centrality dependence are studied in detail. The overall values of the modification factor are found to provide strong constraints on the lifetime of the dense matter.Comment: 6 pages in RevTex with 3 postscript figure

Dielectric constants of soils at microwave frequencies-2

The dielectric constants of several soil samples were measured at frequencies of 5 and 19 GHz using the infinite transmission line method. The results of these measurements are presented and discussed with respect to soil types and texture structures. A comparison is made with other measurements at 1.4 GHz. At all three frequencies, the dependence of dielectric constant on soil moisture can be approximated by two straight lines. At low moisture, the slope is less than at high moisture level. The intersection of the two lines is believed to be a function of soil texture