High Resolution Rydberg Spectroscopy of Ultracold Rubidium Atoms

Abstract

A xelG rabow ski ,R ol f H ei dem ann, R obert L ow ,J urgen Stuhl er, and T i l m an Pfau 5.Physikal isches Institut, U niversit at Stuttgart, Pfa enwal dring 57, 70550 Stuttgart, G erm any (D ated: A ugust 25,2016) W e present experi m ents on tw o-photon exci tati on of 87 R b atom s to R ydberg states. For thi s purpose, tw o conti nuous-w ave (cw )-l aser system s for both 780 nm and 480 nm have been set up. T hese system s are opti m i zed to a sm al l l i new i dth (w el l bel ow 1 M H z) to get both an e ci ent exci tati on process and good spectroscopi c resol uti on. To test the perform ance ofour l aser system , w e i nvesti gated the Stark spl i tti ng ofR ydberg states. For n= 40 w e w ere abl e to see the hyper ne l evel sspl i tti ng i n the el ectri cal el d fordi erent nestructure states. To show the abi l i ty ofspati al l y sel ecti ve exci tati on to R ydberg states,w e exci ted rubi di um atom s i n an el ectri cal el d gradi ent and i nvesti gated both l i new i dthsand l i neshi fts. Furtherm ore w e w ere abl e to exci te the atom ssel ecti vel y from the tw o hyper ne ground states to R ydberg states. Fi nal l y,w e i nvesti gated the A utl er-Tow nes spl i tti ng ofthe 5S 1=2 ! 5P 3=2 transi ti on vi a a R ydberg state to determ i ne the R abifrequency ofthi s exci tati on step. I. IN T R O D U C T IO N

Quantum information with Rydberg atoms

“…The first example of Rydberg spectroscopy with narrow linewidth lasers using this approach was a study of Autler-Townes spectra in a cold 85 Rb sample (Teo et al, 2003). Autler-Townes spectra in Rydberg excitation were also studied later in (Grabowski et al, 2006). Three photon excitation schemes with narrow linewidth lasers have also been used in experiments with Cs (Vogt et al, 2006) and Rb (Thoumany et al, 2009a).…”

Optical transfer cavity stabilization using current-modulated injection-locked diode lasers

“…An alternative technique is to use an optical cavity to "transfer" the stability from a stabilized reference laser to the target laser. 2,3,4,5,6,7,8,9 One way this may be accomplished is by repetitively scanning the length of a "transfer cavity" (TC) with piezoelectric transducers (PZTs). The transmission fringe positions of the target laser are then compared to the reference laser using specialized digital circuitry 2 or computers.…”

“…Scanning the cavity length may be avoided by making the transmission maxima of both the reference laser and the target laser coincide at the same cavity length. 5,6,7,8,9 In this case, the cavity is locked to the reference laser and the target laser is locked to the cavity using analog circuitry. To make the fringes coincide it is possible to frequency shift either the reference or the target laser using an electro-optic modulator (EOM) 5 or an acoustooptic modulator (AOM).…”

“…To make the fringes coincide it is possible to frequency shift either the reference or the target laser using an electro-optic modulator (EOM) 5 or an acoustooptic modulator (AOM). 7,9 In this way, frequency stability and precise RF frequency tunability can be obtained. Since, in general, frequency shifts on the order of the free spectral range of the cavity may be required, the modulator in these systems should be capable of producing a broad-band of frequency shifts in order to avoid an inconveniently long transfer cavity.…”

Experiments with Highly-Ionized Atoms in Unitary Penning Traps

“…This will be placed orthogonal to the ion path to allow the injection of the rubidium beam into the center of the re-capture Penning trap. A two- [70] or three-laser excitation scheme [71] can be used to excite the rubidium atoms to a Rydberg state. These Rydberg rubidium atoms will be injected into the Penning trap, where they will undergo resonant charge exchange [72] with trapped, fully-ionized helium and neon ions to form one-electron ions in Rydberg states.…”