Description
Light-pulse atom interferometry (LPAI) is a preeminent method for precision measurements of inertial forces and fundamental physical constants. In general, the sensitivity of LPAI can be enhanced by large momentum transfer (LMT), which increases the separation between the interferometer paths before their recombination. Meanwhile, maintaining a high interference-fringe contrast is essential for high-precision phase readout. In practice, however, high-fidelity matter-wave beam splitters and mirrors are often limited by laser-intensity inhomogeneity and low-frequency technical noise.
Here, we demonstrate a high-contrast large-momentum-transfer atom interferometry based on stimulated Raman transitions. Robust atom-optical pulses based on the biased rotations (BR) are implemented on the ground-state hyperfine levels of $^{87}\rm{Rb}$ to parallelly control three pairs of atomic spins tates. These pulses achieve a control fidelity of approximately $99\%$ and tolerate optical-intensity variations of up to $\pm50\%$. By combining these robust pulses with nanosecond spin-dependent kicks and efficient AOM-based $\pm k_{eff}$ -swapping, we realize a $34\hbar k$ transfer Mach–Zehnder interferometer with $>50\%$ contrast. The interferometer is capable of resolving acceleration-induced displacements at a few nanometer level, using merely $10^4$ atoms.
