Fig. 1: Sources of noise in field-deployed atom-interferometric sensors and error-suppression using error-robust pulses.
From: Enhancing the sensitivity of atom-interferometric inertial sensors using robust control
a Space-time diagram for an order-n Bragg pulse atom interferometer in the Mach–Zehnder configuration, employing conventional Gaussian pulses as mirror and beamsplitters separated by equal interrogation times T and subject to a constant acceleration a in the -z direction. b and c show the waveforms for Gaussian (στ = 15 μs) and error-robust Bragg mirror pulses of order-3 (6 ℏk), respectively. (d-f) show schematic representations of the relevant noise processes under consideration (see main text). Noise source: d the finite atomic momentum width of the atomic source in the longitudinal z direction; e the thermal expansion of the atom cloud in the transverse xy plane across a Gaussian beam; and f the effect of a constant platform acceleration transverse to the measurement axis. The state-transfer fidelity of the Gaussian and error-robust mirror pulses as a function of atomic z momentum and laser intensity variation (plotted as a fraction of the peak intensity I0) is depicted in g and h, respectively, highlighting the improvement afforded by the error-robust pulse.
