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Excited state spatial distributions in a cold strontium gas. Graham Lochead. Outline. Motivation and Rydberg physics Experimental details Rydberg spatial distributions. The strontium Rydberg project – April 2012. Strong interactions. E int > E pot ,E kin.
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Excited state spatial distributions in a cold strontium gas Graham Lochead
Outline Motivation and Rydberg physics Experimental details Rydberg spatial distributions The strontium Rydberg project – April 2012
Strong interactions Eint > Epot,Ekin Problem: Correlations make modelling difficult Solution: Simulate in controlled environment The strontium Rydberg project – April 2012
Quantum simulator Need single site addressability … Need strong interactions …Rydberg atoms Weitenberg et al, Nature 471, 319–324 (2011) The strontium Rydberg project – April 2012
Rydberg properties High principal quantum number n Ionization limit n = 68 n = 67 n = 8 n = 66 n = 7 Properties H~ 0.1 nm n = 6 n = 5 n = 100~ 1 μm The strontium Rydberg project – April 2012
Rydberg physics Strong, controllable interactions The strontium Rydberg project – April 2012
Dipole blockade Interaction shift Energy Separation One excitation per atom pair when The strontium Rydberg project – April 2012
Experimental blockade Saturation of excitation H. Schempp et al, Phys. Rev. Lett. 104, 173602 (2010) CNOT gate operation L. Isenhower et al, Phys. Rev. Lett. 104, 010503 (2010) The strontium Rydberg project – April 2012
Experimental plan The strontium Rydberg project – April 2012
Project aim Investigate excited state spatial distributions Ground state Excited state Column density Position T. Pohl et al, Phys. Rev. Lett. 104, 043002 (2010) The strontium Rydberg project – April 2012
Cold atom setup Zeeman slowed atomic beam 5 x 106 strontium atoms at ~5 mK 2 x 109 atoms/cm3 Rydberg laser locked using EIT R. P. Abel et al, Appl. Phys. Lett. 94, 071107 (2009) The strontium Rydberg project – April 2012
Coherent population trapping 5sns(d) Ions detected on MCP Ions Rydberg atoms Sub natural linewidth Control mJ λ2 = 413 nm 5s5p λ1 = 461 nm 5s2 The strontium Rydberg project – April 2012
Autoionization 5s Sr+ e- 5pns(d) λ3 = 408 nm 5s Sr+ 5sns(d) λ2 = 413 nm 5s5p Resonant ionization Independent of excitation State selective λ1 = 461 nm 5s2 J. Millen et al, Phys. Rev. Lett. 105, 213004 (2010) The strontium Rydberg project – April 2012
Focusing and translating The strontium Rydberg project – April 2012
Spatial distribution Focus coupling beam as well Scan one direction along ensemble Ground state from camera image The strontium Rydberg project – April 2012
2D spatial distribution Multiple slices → 2D spatial map Ground state Excited state The strontium Rydberg project – April 2012
Looking for blockade Vary density of ground state The strontium Rydberg project – April 2012
Looking for blockade No blockade so far Denser sample needed → second stage cooling → dipole trap The strontium Rydberg project – April 2012
Summary Rydberg states have strong interactions Coherently excited cold strontium to Rydberg states Measured excited state spatial distributions The strontium Rydberg project – April 2012
The team Matt Jones Charles Adams Me Danielle Boddy Daniel Sadler Christophe Vaillant The strontium Rydberg project – April 2012
Laser stabilization 5sns(d) λ2 = 413 nm 5s5p λ1 = 461 nm 5s2 R. P. Abel et al, Appl. Phys. Lett. 94, 071107 (2009) The strontium Rydberg project – April 2012
