Transitions, dynamics, and spin squeezing in a ferromagnetic spinor condensate

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

The experimental research program continues experiments examining the collective behavior of a novel atomic gas: a spinor Bose-Einstein condensate (BEC) of Rb-87. This work is at the crossover between condensed-matter physics and ultracold atomic physics. This "crossover" region is a rewarding area to study strongly correlated systems that are far from equilibrium. The environment of ultracold atoms provides an exceptional tool to study dynamics with minimal coupling to a dissipative thermal environment that plagues conventional solid or liquid systems. The general theme of the project is to study the role of thermal or quantum fluctuations in determining the nature of the dynamics at the transitions. Of particular interest are the dynamics at quantum phase transitions, at which correlations proliferate, dominate the behavior of the system, and rapidly change its character. The research will shed light on the thermal properties of spinor gases. In particular, the project will characterize quantum dynamics and topological defect formation at a quantum phase transition which connects quantitatively to scaling behavior and critical exponents, directly observe spin vortices in a two-dimensional Bose gas in which the Berezinskii-Kosterlitz-Thouless (BKT) mechanism of vortex/antivortex generation and pairing should occur, and achieve spatially-resolved spin squeezing in a spinor BEC. One of the broader impacts of this work is to use the magnetization-sensitive imaging technique developed to make precision measurements of magnetic fields over small areas, which could have both scientific and technological applications. Further, undergraduates, graduate students, and postdoctoral fellows will be trained in ultracold atom research. The program also includes a component extending developments from modern ultracold atomic physics to undergraduate education by developing experiments for undergraduate teaching laboratories.