Laser Trapping and Cooling of Atoms
Laser cooling methods have made a dramatic impact on physics, resulting in three Nobel Prizes. Laser-cooled atoms are used for Bose-Einstein condensation, atomic clocks, ultra-cold collisions, and quantum information processing. Some of the contributions of Prof. Walker and the Atom Trainers are:
- First diode-laser atom trap (Cs), light-intensity dependence of ultracold collisions
- Discovery and explanation of light-induced collective phenomena in traps
- First Magneto-optical Trap of Rb atoms.
- Spin-polarized trapping of atoms.
- First observation of Landau-Zener excitation in ultracold collisions.
- First use of trapped atoms as target for scattering experiments.
- Demonstration of funnel-loaded trap
- Spatial heterodyne imaging of atoms– 1/1000 photon per atom.
- New concepts in single atom, single photon sources
- Record trapped-atom densities in Holographic Atom Trap
- High fidelity quantum manipulation of atoms in an array of traps
- Coherent Rabi Oscillations With Rydberg Atoms
- Rydberg Blockade of single atoms 10 μm apart.
- First Neutral Atom CNOT gate
- Deterministic entanglement of neutral atom pairs
- Review article on quantum information with Rydberg atoms
- Production of Atomic Fock states using Rydberg blockade
- Coherence and blockade of W-states of ensembles
- Non-destructive readout of atomic qubits
- Continuously tunable Rydberg RF detector
Spin-polarized atoms
Optical Pumping is an important method for producing spin polarized samples of atoms and nuclei for magnetic-resonance imaging, polarized ion beams for accelerators, targets for scattering experiments, and high sensitivity detectors such as magnetometers. Major contributions include:
- Origin of spin-rotation interaction in alkali–noble-gas molecules
- Reliable estimates of spin-exchange and spin-relaxation rates
- Prediction (subsequently experimentally confirmed by groups at Argonne and Erlangen) of
nuclear polarization of H and D atoms by spin-exchange at high fields. - Discovery of alkali-alkali spin-relaxation due to triplet dimer formation
- Invention of new narrow-band high power laser sources
- Discovery of Xe-Xe molecular spin relaxation
- State-of-the-art measurements of spin-relaxation rates.
- Hybrid spin-exchange optical pumping.
- Discovery of ‘X-factor’ polarization limits of Rb-3He.
- Major review article on spin-exchange optical pumping.
- Novel method for atomic magnetometry
- Discovery of angular momentum selection rule violation
- First detection of fetal magnetocardiography with an atomic magnetometer
- Xe comagnetometry search for axion-like particles
- Demonstration of synchronous spin-exchange optical pumping
- High performance co-magnetometry using Xe isotopes