Excitation control of a cold strontium Rydberg gas Graham Lochead, 12/12/11
Team strontium Matt Jones Charles Adams Me Danielle Boddy Dan Sadler Christophe Vaillant Graham Lochead, 12/12/11
Rydberg physics Rydberg atoms: States of high principal n Strong, tunable interactions Ground state Excited state Column density Position Graham Lochead, 12/12/11
Spatial autoionization 5pns(d) λ3 = 408 nm 5s Sr+ 5sns(d) λ2 = 413 nm 5s5p λ1 = 461 nm 5s2 Graham Lochead, 12/12/11
Rydberg transition saturation Outline Quantization axis Focused coupling beam Rydberg transition saturation Graham Lochead, 12/12/11
Experimental procedure ~106 atoms at 5 mK Camera image for atom number 408 is focused to 10 μm Translation stage / probe …frequency stepped Ions detected on an MCP Probe + Coupling (1 μs) 408 pulse (1 μs) Electric field pulse (5 μs) MOT + Zeeman MOT + Zeeman Time Repeat Graham Lochead, 12/12/11
States degenerate – can’t select Quantization axis mJ = -2 -1 +1 +2 J = 2 J = 1 J = 0 States degenerate – can’t select Stray field broadens spectrum Graham Lochead, 12/12/11
Magnetic field splits degeneracy Quantization field Magnetic field splits degeneracy Stretched states strongest coupled Can select mJ state Förster zeros avoided Graham Lochead, 12/12/11
Swtich as fast as possible Eddy currents a problem Field switch on Need to switch field on Swtich as fast as possible Eddy currents a problem Graham Lochead, 12/12/11
Focusing coupling laser Unaddressed Rydberg atoms Why? 1D geometry Better internuclear projection Graham Lochead, 12/12/11
Focused coupling laser Similar lens setup to autoionizing laser Translate 408 to find focus Graham Lochead, 12/12/11
Large increase in Rabi frequency “Saturation” effect Large increase in Rabi frequency “Saturation” seen in amplitude Not Coulomb blockade as no shift 3-level OBE theory incorrect Graham Lochead, 12/12/11
Can excite specific mJ states Summary Can excite specific mJ states Focused coupling laser Saturation effect to investigate Graham Lochead, 12/12/11