A multi-state interferometer on an atom chip

Abstract

Matter-wave interferometry is a powerful tool for high-precision measurements of the quantum properties of atoms, many-body phenomena and gravity. The most precise matter-wave interferometers exploit the excellent localization in momentum space and coherence of the degenerate gases. Further enhancement of the sensitivity and reduction of complexity are crucial conditions for the success and widening of their applications. Here we introduce a multistate interferometric scheme that offers advances in both these aspects. The coherent coupling between Bose-Einstein condensates in different Zeeman states is used to generate high-harmonic output signals with an enhanced resolution and the maximum possible interferometric visibility. We demonstrate the realization of such an interferometer as a compact, easy to use, atomchip device. This provides an alternative method for the measurement of the light-atom and surface-atom interactions and enables the application of multiparameter sensing schemes in cold-atom interferometry.

Fifteen years of cold matter on the atom chip: promise, realizations, and prospects

“…Another example is the demonstration, by the Cataliotti group, of Ramsey interferometry with all five levels of the hyperfine state of [ 342 ]. Later on, the same group developed a scheme for preparing any internal state at will with atoms in the hyperfine state manifold [ 338 ] (Figure 28 ).…”

Bend-free multiarm interferometers on optical chips

“…Figure 3: a)-d) Fringe patterns of interferometers built using the couplers from figure 2 a)-d), respectively, under the assumption that the waveguides do not interact in the sensing region. The total intensity of the input state is normalized to 1. e) 5-arm interferometer constructed with the 1 × 5 couplers with the light distributed equally between the next-to-nearest ports (1,3,5,7,9). The coupler is based on the 9-waveguide array with the coupling coefficients a 1,2 = a 8,9 = 4.029, a 2,3 = a 7,8 = 2.482, a 3,4 = a 6,7 = 2.615, a 4,5 = a 5,6 = 1 found in [20].…”

“…This renders the transfer matrix T sens j,k = e −i(j∆Φ)δ j,k , where ∆Φ is the phase change in the fist arm, j∆Φ the phase change in j th arm and δ j,k the Kronecker symbol. This concept has been corroborated in a free-space optical quantum Fourier interferometer [4], as well as an atomic multi-state interferometer [3]. In an optical fiber or integrated interferometer, a linear phase distribution can be achieved by a temperature gradient across the chip [23], insertion of optofluidic channels of different lengths [24,25], integrated electro-optical modulators [26], etc.…”

“…Here, we consider two types of couplers that produce binomial or equal intensity distributions at the output. The former are intrinsic to the atom interferometers and are well-described by Clebsch-Gordan coupling coefficients [3]. Their photonic analogues have been exploited in realisation of the faithful information transfer in photonic lattices [16].…”

“…Thus achievable sensitivity scaling 1/P is known as Heisenberg limit [1]. An alternative way to improve the measurement outcome is the multiplexing of interferometer modes which can be seen as a super-resolving technique [2,3,4]. For the phase sensing by N < P uncorrelated interferometric modes, the maximum sensitivity enhancement over the shot-noise limit is P/N [5].…”