J. D. D. Martin

Spectroscopic Observation of Resonant Electric Dipole-Dipole Interactions between Cold Rydberg Atoms

Resonant electric dipole-dipole interactions between cold Rydberg atoms were observed using microwave spectroscopy. Laser-cooled 85Rb atoms in a magneto-optical trap were optically excited to 45d(5/2) Rydberg states using a pulsed laser. A microwave pulse transferred a fraction of these Rydberg atoms to the 46p(3/2) state. A second microwave pulse then drove atoms in the 45d(5/2) state to the 46d(5/2) state, and was used as a probe of interatomic interactions. The spectral width of this two-photon probe transition was found to depend on the presence of the 46p(3/2) atoms, and is due to the resonant electric dipole-dipole interaction between 45d(5/2) and 46p(3/2) Rydberg atoms.

Enhancement of Rydberg Atom Interactions Using ac Stark Shifts

The ac Stark effect was used to induce resonant energy transfer between translationally cold 85Rb Rydberg atoms. When a 28.5 GHz dressing field was set at specific field strengths, the two-atom dipole-dipole process 43d5/2+43d5/2-->45p3/2+41f was dramatically enhanced, due to induced degeneracy of the initial and final states. This method for enhancing interactions is complementary to dc electric-field-induced resonant energy transfer, but has more flexibility due to the possibility of varying the applied frequency.

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

It is demonstrated that rf current modulation of a frequency stabilized injection-locked diode laser allows the stabilization of an optical cavity to adjustable lengths, by variation of the rf frequency. This transfer cavity may be used to stabilize another laser at an arbitrary wavelength, in the absence of atomic or molecular transitions suitable for stabilization. Implementation involves equipment and techniques commonly used in laser cooling and trapping laboratories and does not require electro- or acousto-optic modulators. With this technique we stabilize a transfer cavity using a rf current-modulated diode laser which is injection locked to a 780nm reference diode laser. The reference laser is stabilized using polarization spectroscopy in a Rb cell. A Ti:sapphire ring laser at 960nm is locked to this transfer cavity and may be precisely scanned by varying the rf modulation frequency. We demonstrate the suitability of this system for the excitation of laser cooled Rb atoms to Rydberg states.

Energy shifts of Rydberg atoms due to patch fields near metal surfaces

The statistical properties of patch electric fields due to a polycrystalline metal surface are calculated. The fluctuations in the electric field scale like 1/z{sup 2} when z>>w, where z is the distance to the surface and w is the characteristic length scale of the surface patches. For typical thermally evaporated gold surfaces these field fluctuations are comparable to the image field of an elementary charge, and scale in the same way with distance to the surface. Expressions for calculating the statistics of the inhomogeneous broadening of Rydberg-atom energies due to patch electric fields are presented. Spatial variations in the patch fields over the Rydberg orbit are found to be insignificant.

Determination of the {sup 85}Rb ng-series quantum defect by electric-field-induced resonant energy transfer between cold Rydberg atoms

Resonant energy transfer between cold Rydberg atoms was used to determine Rydberg atom energy levels, at precisions approaching those obtainable in microwave spectroscopy. Laser cooled

Coherent manipulation of cold Rydberg atoms near the surface of an atom chip

^{85}\mathrm{Rb}

ac electric-field-induced resonant energy transfer between cold Rydberg atoms

atoms from a magneto-optical trap were optically excited to

Rydberg atoms with a reduced sensitivity to dc and low-frequency electric fields

32{d}_{5∕2}

Reduction of the dc electric field sensitivity of circular Rydberg states using non-resonant dressing fields

Rydberg states. The two-atom process

Understanding Pound-Drever-Hall locking using voltage controlled radio-frequency oscillators: An undergraduate experiment

32{d}_{5∕2}+32{d}_{5∕2}\ensuremath{\rightarrow}34{p}_{3∕2}+30g