CONTINUOUS OBSERVATION OF MAGNETIZATION

IN A SPINOR BOSE-EINSTEIN CONDENSATE

Sebastian Jung, Stephen Maxwell, Yingmei Liu, and Paul Lett

National Institute of Standards & Technology, Atomic Physics Division

100 Bureau Drive, Stop 8424, Gaithersburg, MD 20899-8424, USA

Optically trapped BEC is almost ten years old, but the rich physics of ultracold spin-changing collisions is only now being studied in detail. While collisions in a thermal gas are often thought of as random, incoherent events, in a Bose-Einstein condensate (BEC) the coherent nature of collisions becomes clear. We make use of an optically trapped sodium BEC of spin-1 to explore equilibria and dynamics in a system allowing spin-changing collisions. Spin-1 rubidium BEC spontaneously breaks up into ferromagnetic domains, while spin-1 sodium is antiferromagnetic and maintains a single spatial domain for the life of the BEC. At NIST we have exploited sodium's stability to study the nonlinear dynamics of Zeeman population oscillations. In a new series of experiments, we continuously measure the transverse magnetization of the evolving BEC spin with a Faraday polarimeter. We observe the collective Larmor precession of the BEC in real time, limited only by the scattering rate of the probe beam. Spin-collision dynamics are manifest as modulation of the Larmor carrier.

Category: Physics

Name:                                    Sebastian Jung

Mentor's name:                    Paul Lett

Division:                                Atomic Physics Division (842)

Laboratory:                          Laser Cooling and Trapping Group

Address:                                Rm. B241, Bldg. 216, Stop 8424

Telephone #:                        (301) 975-2576

FAX #:                                   (301) 975-8272

email:                                     sebastian.jung@nist.gov

Not a Sigma Xi member

Name:                                    Stephen Maxwell

Mentor's name:                    Paul Lett

Division:                                Atomic Physics Division (842)

Laboratory:                          Laser Cooling and Trapping Group

Address:                                Rm. B141, Bldg. 216, Stop 8424

Telephone #:                        (301) 975-4950

FAX #:                                   (301) 975-8272

email:                                     stephen.maxwell@nist.gov

Not a Sigma Xi member

Name:                                    Yingmei Liu

Mentor's name:                    Paul Lett

Division:                                Atomic Physics Division (842)

Laboratory:                          Laser Cooling and Trapping Group

Address:                                Rm. B255, Bldg. 216, Stop 8424

Telephone #:                        (301) 975-8571

FAX #:                                   (301) 975-8272

email:                                     yingmei.liu@nist.gov

Not a Sigma Xi member