Research Projects

 Bose-Einstein condensates

Working with Rb BEC

Rubidium atoms are loaded into a 3D MOT from a 2D+ MOT. Then the cold atoms are further loaded into a crossed optical dipole trap (XODT) for further cooling. Force evaporation leads to the formation of Bose-Einstein condensates in the XODT.

Bose-Einstein condensation of rubidium atoms in a crossed optical dipole trap (XODT).

JPB 50, 155302 (2017).

Stern-Gerlach time-of-flight (TOF) imaging reveals this condensate a spin-1 condensate.

JPB 50, 155302 (2017).

A BEC loaded into a square optical lattice forms either a superfluid or Mott-insulator state (TOF images).

 Nanodiamond

Working with nano-diomands

Nanodiamonds are excited by a green laser, and their fluorescent lights are collected and imaged under a microscope. The probe laser also serves to optically pump and initialize the internal spins. Spin resonance images are obtained by simultaneously applying a resonant microwave driving spin tansitions.

(a) Electron spin resonance frequency shifts due to temperature changes is at a rate of -75 kHz/K. (b) pump-probe time-resolved nanodiamond thermometer has a fast response time.

Nano Lett. 15, 3945-3952 (2015). 

(c) Diamond crystal (sp3 bonding) allows four possible orientations of NV centers. (d) A vector B field applied along different directions which gives 2 to 4-orientation groups to be degenerate under Zeeman splitting.

 Ytterbium ion


Working with Yb ions

Ytterbium atoms are photo-ionized and loaded into a Paul trap made of four blades and two needle-endcaps. The Yb+ ions are laser cooled and manipulated in the trap for metrology or quantum computing applications.