BEC 3 — NaLi Molecule Experiment

Check out BEC3 lab website!

Collisional Dynamics of NaLi Molecules

We have succeeded in forming NaLi molecules in their triplet ground state from an ultracold
mixture of Na and Li atoms. This is done in two steps. First, loosely bound Feshbach molecules
are created by the careful sweeping of a magnetic field around a Feshbach resonance, where the energy
for a state of two free atoms becomes degenerate with the energy for the bound molecular state of
the two atoms, but with different internal electronic and nuclear spins is done. Second, loosely bound
molecules are transferred to tightly bound triplet ground state molecules via Stimulated Raman
adiabatic passage(STIRAP).

The NaLi molecule, the lightest bi-alkali molecule, in the triplet ground state have a long collisional lifetime
which allows us to investigate the complexity of chemical reactions by finding links to scattering theory.
We have previously observed internal state-dependent collision of Na-NaLi mixture and have seen favorable
collisional properties in their fully stretched states enabling collisional cooling of NaLi molecules. We are
interested in the observation of magnetically controlled collision of Na-NaLi mixture. This can give positive
influence on understanding molecular collisions in the quantum regime and discovering a more efficient way
of sympathetic cooling of molecules.

Our recent work can be found here.

Four photon STIRAP from ultracold Na and Li to NaLi molecules

Usually, when the magnetic field is swept across a Feshbach resonance, the atom pair is adiabatically
transferred to the molecular bound state because the two are coupled by the hyperfine interactions in
the system. However, in the Na + Li system, such hyperfine-induced Feshbach resonances are at very high
magnetic fields that are out of experimental range. Instead, we worked around a Feshbach resonance
at 745G that is produced by weak dipole-dipole coupling between the atoms. This coupling term is orders
of magnitude weaker than the hyperfine interaction, meaning that the requirements for successful adiabatic
conversion of atom pairs to molecules become extraordinarily demanding. We are able to create no more
than a few percent of our initial atomic mixture to Feshbach molecules only after implementing magnetic
field stabilizing circuits by carefully characterizing our experimental system.  and adiabatic sweep across
the very narrow, ~mG wide range of the Feshbach resonance, and then immediately jump the field away
from resonance again to isolate the molecules for imaging.

We are planning to transfer our initial mixture of atoms to loosely bound molecules via two-photon process
bridged by a carefully selected excited molecular state. This will allow freedom in internal states of mixture
of Na and Li we start with in order to make NaLi molecules which is not the case if we do magnetic transfer
via Feshbach resonance. We are hoping to simplify our experimental setup by choosing our initial states of
Na and Li mixture to be magnetically trappable.

Current Members

Graduate Students

Hongyin Liu — hongyin@mit.edu

Hyo Sun Park — hyosun1@mit.edu

Visiting Students

Paul Del Franco — pdelfran@mit.edu

Postdoctoral Associates

Dr. Georgi Gary Rozenman — gary95@mit.edu

Principle Investigator

Wolfgang Ketterle — ketterle@mit.edu

Publications

G.-B. Jo, Y. Shin, S. Will, T. A. Pasquini, M. Saba, W. Ketterle,
D. E. Pritchard, M. Vengalattore, and M. Prentiss
Long Phase Coherence Time and Number Squeezing of Two
Bose-Einstein Condensates on an Atom Chip
Phys. Rev. Lett. 98, 030407 (2007) Paper

T. A. Pasquini, M. Saba, G. Jo, Y. Shin, W. Ketterle, D. E. Pritchard,
T. A. Savas, N. Mulders
Low Velocity Quantum Reflection of Bose-Einstein Condensates
Phys. Rev. Lett. 97, 260402 (2006) Paper

Y. Shin , G.-B. Jo , M. Saba , T.A. Pasquini , W. Ketterle , and D.E. Pritchard
Optical Weak Link between Two Spatially Separate
Bose-Einstein Condensates
Phys. Rev. Lett. 95, 170402 (2005)

Y. Shin, C. Sanner, G.-B. Jo, T. A. Pasquini, M. Saba, W. Ketterle,
D. E. Pritchard, M. Vengalattore and M. Prentiss
Interference of Bose-Einstein Condensates on an Atom Chip
Phys. Rev. A 72 , 021604(R) (2005) Paper 

M. Saba, T.A. Pasquini, C. Sanner, Y. Shin, W. Ketterle, and D.E. Pritchard
Continuous Measurement of the Relative Phase of Two
Bose-Einstein Condensates Using Light Scattering
Science 307, 1945-1948 (2005) Paper and Press Report

Y. Shin, M. Saba, M. Vengalattore, T. A. Pasquini, C. Sanner,
A. E. Leanhardt, M. Prentiss, D. E. Pritchard, and W. Ketterle
Dynamical Instability of a Doubly Quantized Vortex
in a Bose-Einstein Condensate
Phys. Rev. Lett. 93, 160406 (2004)

T.A. Pasquini, Y. Shin, C. Sanner, M. Saba, A. Schirotzek,
D.E. Pritchard, and W. Ketterle
Quantum Reflection of Atoms from a Solid Surface
at Normal Incidence
Phys. Rev. Lett. 93, 223201 (2004) Paper

Y. Shin, M. Saba, A. Schirotzek, T. A. Pasquini, A. E. Leanhardt,
D. E. Pritchard, and W. Ketterle
Distillation of Bose-Einstein Condensates in a Double-Well Potential
Phys. Rev. Lett. 92, 150401 (2004) Summary and Paper

Y. Shin, M. Saba, T. Pasquini, W. Ketterle, D.E. Pritchard, and A.E. Leanhardt
Atom Interferometry with Bose-Einstein Condensates in a
Double-Well Potential
Phys. Rev. Lett. 92, 050405 (2004) Summary and Paper 

A. E. Leanhardt, T. A. Pasquini, M. Saba, A. Schirotzek, Y. Shin,
D. Kielpinski, D. E. Pritchard, and W. Ketterle
Adiabatic and Evaporative Cooling of Bose-Einstein Condensates
Below 500 Picokelvin
Science 301, 1513-1515 (2003) Summary and Paper
Press Report and Photos
How to achieve and measure ultralow temperatures

A.E. Leanhardt, Y. Shin, D. Kielpinski, D.E. Pritchard, and W. Ketterle
Coreless Vortex Formation in a Spinor Bose-Einstein Condensate
Phys. Rev. Lett. 90, 140403 (2003) Summary and Paper

A.E. Leanhardt, Y. Shin, A.P. Chikkatur, D. Kielpinski,
W. Ketterle, and D.E. Pritchard
Bose-Einstein Condensates Near a Microfabricated Surface.
Phys. Rev. Lett. 90, 100404 (2003) Summary and Paper

A.E. Leanhardt, A. Görlitz, A.P. Chikkatur, D. Kielpinski,
Y. Shin, D.E. Pritchard, and W. Ketterle
Imprinting Vortices in a Bose-Einstein Condensate
Using Topological Phases
Phys. Rev. Lett. 89, 190403 (2002) Summary and Paper

A. P. Chikkatur, Y. Shin, A. E. Leanhardt, D. Kielpinski, E. Tsikata,
T. L. Gustavson, D. E. Pritchard, and W. Ketterle
A Continuous Source of Bose-Einstein Condensed Atoms
Science 296, 2193-2195 (2002), published online in Science Express
on May 16, 2002
Summary, Paper and Press Report

A.E. Leanhardt, A.P. Chikkatur, D. Kielpinski, Y. Shin, T.L. Gustavson,
W. Ketterle, and D.E. Pritchard
Propagation of Bose-Einstein Condensates in a Magnetic Waveguide
Phys. Rev. Lett. 89, 040401 (2002) Summary and Paper

T.L.Gustavson, A.P.Chikkatur, A.E.Leanhardt, A.Görlitz, S.Gupta,
D.E.Pritchard, and W.Ketterle
Transport of Bose-Einstein Condensates with Optical Tweezers
Phys. Rev. Lett. 88, 020401 (2002) Summary, Paper and Images
Press Report 1 and 2

History

Guinness World Record for lowest temperature ever produced

A. E. Leanhardt, T. A. Pasquini, M. Saba, A. Schirotzek, Y. Shin, D. Kielpinski, D. E. Pritchard, and W. Ketterle
Adiabatic and Evaporative Cooling of Bose-Einstein Condensates Below 500 Picokelvin
Science 301, 1513-1515 (2003) Summary and Paper
Press Report and Photos
How to achieve and measure ultralow temperatures

First realization of optical transport of ultracold atoms between two separate vacuum chambers

A. P. Chikkatur, Y. Shin, A. E. Leanhardt, D. Kielpinski, E. Tsikata, T. L. Gustavson, D. E. Pritchard, and W. Ketterle
A Continuous Source of Bose-Einstein Condensed Atoms
Science 296, 2193-2195 (2002), published online in Science Express on May 16, 2002
Summary, Paper and Press Report

T.L.Gustavson, A.P.Chikkatur, A.E.Leanhardt, A.Görlitz, S.Gupta, D.E.Pritchard, and W.Ketterle
Transport of Bose-Einstein Condensates with Optical Tweezers
Phys. Rev. Lett. 88, 020401 (2002) Summary, Paper and Images
Press Report 1 and 2

Former Members

Andre Schirotzek

Yong-Il Shin

Tout Wang

Sebastian Will

Li Jing

Yijun Jiang

Sepehr Ebadi

Ariel Sommer 

Timur Rvachov

Alan Jamison

Hyungmok Son

Juliana Park