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Eric Copenhaver

Publications and source records attributed to Eric Copenhaver.

3 recordsLinked to original sources

Sub-Doppler laser cooling and optical transport of cesium with static magnetic fields

Laser cooling of alkali atoms typically requires time-varying magnetic fields, introducing unwanted coupling between atom preparation and coherent operations. Here we demonstrate sub-Doppler laser cooling and optical transport of alkali atoms in a fully static magnetic-field configuration. Using a blue-detuned Type-II magneto-optical trap (MOT) operating on the closed $F=3 \rightarrow F'=2$ transition of the D2 line in cesium, we achieve temperatures of 17(1) $\mu$K without changing the magnetic-field gradient between cooling stages. This enables direct loading into a shallow optical lattice and transport over 17 cm within the same static-field environment. In contrast to conventional alkali cooling schemes with dynamic fields, our approach establishes a continuous cooling and transport protocol compatible with static-field platforms. These results validate Type-II cooling as a practical technique for alkali atoms and provide a new route toward continuous-operation architectures in sensing and quantum computing.

physics.atom-ph

Measurement of a $^7$Li tune-out wavelength by phase-patterned atom interferometry

Atom interferometers typically use the total populations the interferometer's output ports as the signal, but finer spatial structure can contain useful information. We pattern a matter-wave phase profile onto an atomic sample. An interferometer translates the phase into a measurable pattern in the atomic density that we use perform the first direct precision measurement of the $^7$Li tune-out wavelength near 671 nm. Expressed as a detuning from the $|2S_{1/2},F{=}2\rangle{\rightarrow}|2P_{1/2},F'{=}2\rangle$ transition, we find 3329.3(1.4) MHz for the tensor-shifted tune out of the $|2S_{1/2},F{=}2,m_F{=}0\rangle$ state with $σ^\pm$ light polarization and 3310.1(4.9) MHz for the tune out of the the scalar polarizability. This technique may be generalized for directly sensing spatially varying phase profiles.

physics.atom-ph

Recoil-sensitive lithium interferometer without a subrecoil sample

We report simultaneous conjugate Ramsey-Bordé interferometers with a sample of low-mass (lithium-7) atoms at 50 times the recoil temperature. We optically pump the atoms to a magnetically insensitive state using the $2S_{1/2} - 2P_{1/2}$ line. Fast stimulated Raman beam splitters address a broad velocity class and unavoidably drive two conjugate interferometers that overlap spatially. We show that detecting the summed interference signals of both interferometers, using state labeling, allows recoil measurements and suppression of phase noise from vibrations. The use of "warm" atoms allows for simple, efficient, and high-flux atom sources and broadens the applicability of recoil-sensitive interferometry to particles that remain difficult to trap and cool.

physics.atom-ph