Dynamics of a Bose-Einstein Condensate Confined in Magneto-Optical Traps at Finite Temperatures

正人 大矢

Kou Matsui, Hiromitsu Imai, Hironobu Yamaoka +3 more

Bose–Einstein condensates of dilute gaseous sodium atoms were achieved by Zeeman slowing, dual-operation magneto-optical trapping (MOT), temporal dark MOT, polarization gradient cooling, direct confinement in a compressed magnetic field and radio-frequency-induced forced evaporative cooling. The dependence of the temperature of the phase transition on the radial curvature of the magnetic field was studied.

F. Kh. Abdullaev, Bakhtiyor B. Baizakov, V. V. Konotop

B Lu, William Arie van Wijngaarden

The apparatus and procedure required to generate a pure Bose-Einstein condensate (BEC) consisting of about half a million 87Rb atoms at a temperature of <60 nK with a phase density of >54 is described. The atoms are first laser cooled in a vapour cell magneto-optical trap (MOT) and subsequently transferred to an ultra-low pressure MOT. The atoms are loaded into a QUIC trap consisting of a pair of quadrupole coils and a Ioffe coil that generates a small finite magnetic field at the trap energy minimum to suppress Majorana transitions. Evaporation induced by an RF field lowers the temperature permitting the transition to BEC to be observed by monitoring the free expansion of the atoms after the trapping fields have been switched off.PACS Nos.: 03.75.Fi, 05.30.Jp, 32.80.Pj, 64.60.–i

Yeong E. Kim, Alexander L. Zubarev

Mulmat, Christian

This research was focused on the construction of a magneto-optical trap (MOT) to create a Bose-Einstein Condensate (BEC) of 87Rb. The BEC is the coldest of the five states of matter functioning at a minuscule temperature of nanokelvin. A BEC is as close as we can get to absolute zero. Thus making it a valuable tool for researching the fundamental physics of quantum systems. Our setup utilizes both a high pressure and low-pressure MOT. The high-pressure MOT initiates the process with a high vapor density allowing for better Rb collection. The trapped atoms are then transported to the low-pressure MOT where there are no other atoms. Rb atoms are further cooled to a Bose-Einstein condensate temperature and are moved with more current-carrying coils to the glass BEC chamber. In the BEC chamber all Rb atoms are identical at their lowest quantum state. Although the process can be phrased in a few short sentences the setup and characterization of the entire system takes months to years of construction. # 43- 46 Environmental Fellows Program: Student Practicums