Research

CsYb: MicroKelvin Molecules in a Quantum Array

Posted on 16th August 2012
Contributors: Kirsteen Butler, Simon Lee Cornish, Alexander Guttridge, Stephen Hopkins, Stefan Kemp

Outline:

Ultracold dipolar molecules offer a wide range of potential applications in atomic and molecular physics, ranging from precision measurement of fundamental physics to ultracold quantum chemistry. The goal of this project is to create a quantum degenerate mixture of Yb and Cs confined in a 3D optical lattice and subsequently produce ultracold CsYb molecules. Such molecules possess both a magnetic moment and an electric dipole moment, and therefore offer intriguing possibilities for the quantum simulation of lattice spin models.

Latest Results:

We successfully created our first Cs BEC on 30th June 2016. The condensate contained ~ 5 x 104 133Cs atoms. The route to Cs BEC was as follows:

A MOT of 3 x 108 Cs atoms is loaded in 5 s. These atoms are then cooled and compressed via molasses and gradient ramps before being transferred into the Raman lattice. After Raman sideband cooling for 8 ms we obtain 4.5 x107 atoms at T~ 2 µK. These atoms are then transferred into a crossed Resevoir trap created by a 50 W IPG laser at 1070 nm. The reservoir is formed by two 20 W beams crossing at angle of 25˚, with waists 440 µm and 640 µm respectively. We initially load 1.5 x 107 atoms into the reservoir at T= 2.3 µK. We transfer 9 x 105 of these atoms into a dimple trap formed by crossing a 75 µm waist beam with a beam with a 30 µm waist at an angle of 40˚. The bias field is then reduced to 22 G and the sample is evaporatively cooled by reducing the Dimple laser power over 2.5 s. The onset of degeneracy occurs at Tc = 40 nK with N = 7 x 104. We obtain pure condensates of 5 x 104.

 

 

Funding:

 "MMQA: Microkelvin Molecules in a Quantum Array" EP/I012044/1. (Dec. 2010 - Dec. 2015). This project forms part of a collaborative project with the Cold Matter group at Imperial College, London.