Nondestructive interferometric characterization of an optical dipole trap

Abstract

A method for non-destructive characterization of a dipole trapped atomic sample is presented. It relies on a measurement of the phase-shift imposed by cold atoms on an optical pulse that propagates through a free space Mach-Zehnder interferometer. Using this technique we are able to determine, with very good accuracy, relevant trap parameters such as the atomic sample temperature, trap oscillation frequencies and loss rates. Another important feature is that our method is faster than conventional absorption or fluorescence techniques, allowing the combination of high-dynamical range measurements and a reduced number of spontaneous emission events per atom.

Electron Transport Properties and Dielectric Breakdown of Alkyl Monolayers Chemisorbed on a Highly Doped n-Type Si(111) Surface

“…Equation (6) illustrates this idea under the reasonable assumptions of sufficient optical power to render the technical noise negligible and weak absorption of the light. In our case, with 3 × 10 5 photons per pulse, and atomic column density of 2.2 × 10 12 atoms m −2 , both assumptions are valid.…”

Quantum Fisher information and spin squeezing in one-axis twisting model

“…It is believed that spin squeezing which is aroused from quantum correlation effect among individual particles, is closely related to multipartite entanglement [9,11,16,41]. One of the main applications of the SSSs is used to reduce quantum noise and increase the signal-to-noise ratio in spectroscopy [10,11,42,43]. Below, we only consider the parameter ξ 2 K to characterize spin squeezing.…”

“…Due to [J 2 , L] = [J z , L] = 0, the expressions of J 2 , J z and J 2 z remain unchanged as are given by equations (30), (28), and (29). By submitting those solutions into equation (42), one can exactly obtain V − and ξ 2 K . χ 2 for the state of (47) can be numerically calculated based on equations (8) and (9).…”

Spin Squeezing of a Cold Atomic Ensemble with the Nuclear Spin of One-Half

“…The QND measurement of the collective spin is also considerably interesting, and in fact the QND interaction of collective spin of an atomic ensemble (spin-QND interaction) via the Faraday-rotation interaction with linearly-polarized off-resonant light has been proposed [8,9]. An implication is the spin squeezed state [10], which could improve the measurement precision of the atomic clock transition [11,12] and of the permanent electric dipole moment to test the violation of time reversal symmetry [13]. The spin-QND interaction is also useful for implementing continuous-variable quantum information devices, such as quantum memory and quantum teleportation [3,14,15,16,17].…”