Realisation and Characterisation the BEC for 87Rb Atoms

Nihal A Abdulwahhab,Ferruccio Renzoni

doi:10.29196/jubpas.v27i1.2219

Abstract

The Bose-Einstein condensate (BEC) is created in a magnetic trap in the Quadrupole-Ioffe configuration (QUIC). This kind of trap combines an anti-Helmholtz quadrupole field with an offset field produced by a single coil perpendicular to the quadrupole field axis to suppress Majorana transitions. In the quadrupole trap evaporative cooling is performed by using radio frequency, reaching the phase transition to a BEC in the QUIC trap. By using Time of Flight (TOF) technique, the expansion velocity is measured with and which lead to temperature of and It is roughly around the recoil temperature.

Highlights

The first experimental realisation of the Bose-Einstein condensate (BEC) in dilute gases was in 1995 for 87Rb atoms [1]
Atoms are known to be either half integer spin fermions, which cannot occupy the same quantum state according to the Pauli exclusion principle, or integer spin bosons without restriction on the number of atoms occupying the same quantum state
Since the power provided by the diode laser is insufficient for a BEC experiment, a Master Oscillator Power Amplifier (MOPA) system is used as a laser source

Summary

Introduction

The first experimental realisation of the BEC in dilute gases was in 1995 for 87Rb atoms [1]. If a vapour of bosonic atoms is cooled down a very low temperature, and the particles' separation is close to the thermal de Broglie wavelength, the wave packets of the atoms overlap. The system approaches the quantum degeneracy and follows the Bose-. The phase-space density (PSD) denoted by ρ, defined as the particles number in a cubic volume of the thermal de-Broglie wavelength, is used as a quantity to measure the degree of the quantum degeneracy of a system [4, 5]:. Dimensions, the atoms can accumulate in the lowest energy quantum state when the phase space density ρ approaches 2.6 [6]. Laser cooled atoms are neither cold nor dense enough to generate a sufficient phase space density for the BEC transition. The breakthrough in Bose-Einstein condensation happened with the implementation of magnetic traps and evaporative cooling, which enabled far lower temperatures and higher densities than previously reached

Methodology

Experimental results

Temperature measurements

Observation of Bose-Einstein Condensate

Conclusion