2,398 research outputs found
Do People Make Strategic Moves? Experimental Evidence on Strategic Information Avoidance
The strategic commitment moves that game theory predicts players make may sometimes seem counter-intuitive. We therefore conducted an experiment to see if people make the predicted strategic move. The experiment uses a simple bargaining situation. A player can make a strategic move of committing to not seeing what another player will demand. Our data show that subjects do, but only after substantial time, learn to make the predicted strategic move. We find only weak evidence of physical timing effects.strategic moves; commitment; bargaining; strategic value of information; physical timing effects; endogenous timing; experiment
Coherence Properties of Guided-Atom Interferometers
We present a detailed investigation of the coherence properties of beam
splitters and Mach-Zehnder interferometers for guided atoms. It is demonstrated
that such a setup permits coherent wave packet splitting and leads to the
appearance of interference fringes. We study single-mode and thermal input
states and show that even for thermal input states interference fringes can be
clearly observed, thus demonstrating the multimode operation and the robustness
of the interferometer.Comment: 4 pages, 4 figure
Infinite qubit rings with maximal nearest neighbor entanglement: the Bethe ansatz solution
We search for translationally invariant states of qubits on a ring that
maximize the nearest neighbor entanglement. This problem was initially studied
by O'Connor and Wootters [Phys. Rev. A {\bf 63}, 052302 (2001)]. We first map
the problem to the search for the ground state of a spin 1/2 Heisenberg XXZ
model. Using the exact Bethe ansatz solution in the limit of an infinite ring,
we prove the correctness of the assumption of O'Connor and Wootters that the
state of maximal entanglement does not have any pair of neighboring spins
``down'' (or, alternatively spins ``up''). For sufficiently small fixed
magnetization, however, the assumption does not hold: we identify the region of
magnetizations for which the states that maximize the nearest neighbor
entanglement necessarily contain pairs of neighboring spins ``down''.Comment: 10 pages, 4 figures; Eq. (45) and Fig. 3 corrected, no qualitative
change in conclusion
Differential atom interferometry beyond the standard quantum limit
We analyze methods to go beyond the standard quantum limit for a class of
atomic interferometers, where the quantity of interest is the difference of
phase shifts obtained by two independent atomic ensembles. An example is given
by an atomic Sagnac interferometer, where for two ensembles propagating in
opposite directions in the interferometer this phase difference encodes the
angular velocity of the experimental setup. We discuss methods of squeezing
separately or jointly observables of the two atomic ensembles, and compare in
detail advantages and drawbacks of such schemes. In particular we show that the
method of joint squeezing may improve the variance by up to a factor of 2. We
take into account fluctuations of the number of atoms in both the preparation
and the measurement stage, and obtain bounds on the difference of the numbers
of atoms in the two ensembles, as well as on the detection efficiency, which
have to be fulfilled in order to surpass the standard quantum limit. Under
realistic conditions, the performance of both schemes can be improved
significantly by reading out the phase difference via a quantum non-demolition
(QND) measurement. Finally, we discuss a scheme using macroscopically entangled
ensembles.Comment: 10 pages, 5 figures; eq. (3) corrected and other minor change
A quantum beam splitter for atoms
An interferometric method is proposed to controllably split an atomic
condensate in two spatial components with strongly reduced population
fluctuations. All steps in our proposal are in current use in cold atom
laboratories, and we show with a theoretical calculation that our proposal is
very robust against imperfections of the interferometer.Comment: 6 pages, 3 figures, revtex
Squeezed light from spin squeezed atoms
We propose to produce pulses of strongly squeezed light by Raman scattering
of a strong laser pulse on a spin squeezed atomic sample. We prove that the
emission is restricted to a single field mode which perfectly inherits the
quantum correlations of the atomic system.Comment: 5 pages, 2 figures, revtex4 beta
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