Recoil-sensitive lithium interferometer without a subrecoil sample

We report recoil-sensitive Ramsey-Bord\'{e} atom interferometry with a sample of lithium-7 atoms at 300 $\mu K$, well above the atomic recoil temperature of 6 $\mu K$. We overcome the need for additional cooling and velocity selection steps, which decrease phase sensitivity, by spectrally resolving the output ports with 160-ns Raman beam splitters. The large bandwidth pulses drive both conjugate interferometers simultaneously with nearly equal contrast, allowing for state selective detection of the summed interferometer signal. Optical pumping to a magnetically-insensitive state suppresses magnetic dephasing and extends coherence time. Sensitivity comparable to interferometers using large momentum transfer pulses can be attained at interrogation times on the order of 10-ms due to lithium’s high recoil frequency and the increased available atom number. At this time scale, vibration noise is converted to amplitude noise and does not perturb the determination of the recoil frequency from the summed interference signal. In addition to simplifying cooling, increasing atom number and reducing cycle time for faster integration, these techniques broaden the applicability of recoil-sensitive interferometry to particles that remain difficult to trap and cool, like electrons.