Supersolid-Based Gravimeter in a Ring Cavity

Abstract

We propose a novel type of composite light-matter interferometer based on a supersolid-like phase of a driven Bose-Einstein condensate coupled to a pair of degenerate counterpropagating electromagnetic modes of an optical ring cavity. The supersolid-like condensate under the influence of the gravity drags the cavity optical potential with itself, thereby changing the relative phase of the two cavity electromagnetic fields. Monitoring the phase evolution of the cavity output fields thus allows for a nondestructive measurement of the gravitational acceleration. We show that the sensitivity of the proposed gravimeter exhibits Heisenberg-like scaling with respect to the atom number. As the relative phase of the cavity fields is insensitive to photon losses, the gravimeter is robust against these deleterious effects. For state-of-the-art experimental parameters, the relative sensitivity ∆g/g of such a gravimeter could be of the order of 10 −10 -10 −8 for a condensate of a half a million atoms and interrogation time of the order of a few seconds.Introduction.-Precision measurement plays a vital role in fundamental sciences as well as technological applications. Notably, at the beginning of the twentieth century discrepancies between precise measurements and theory led to the birth of quantum mechanics [1]. Interestingly, quantum mechanics itself in turn opened an entirely new avenue in precision measurement. One of its most flourishing branches is quantum metrology, which exploits the quantum-mechanical framework to perform even more precise measurements than it is allowed by classical approaches [2,3]. Remarkable examples include the development of precise "gravimeters" based on quantum mechanical effects.A gravimeter is an apparatus that measures the local gravitational acceleration. It allows to measure, e.g., magma build-up before volcanic eruptions, hidden hydrocarbon reserves, and Earth's tides [4]. In addition, it also allows to test more fundamental aspects of physics such as local Lorentz invariance [5], the isotropy of post-Newtonian gravity [6], and quantum gravity [7]. The current generation of gravimeters include: microelectromechanical gravimeters [4], free-fall gravimeters [8][9][10][11][12], spring-based gravimeters [13,14], superconducting gravimeters [15], optomechanical gravimeters [16,17], and atom interferometers [18][19][20][21][22][23].In the above list, the atom interferometry deserves a special position because of the possibility of harnessing quantum features of many-body systems [24]. In principle, by using entangled resources, it is possible to increase the precision of measurement over the shot-noise limit [25]. However, noise and decoherence limit the creation and use of quantum correlations [26,27], especially for large samples. Hence, sub-shot-noise interferometry is currently restricted to proof-of-principle experiments with atoms [28][29][30][31][32][33][34] as well as photons [35][36][37][38][39].In this Letter, we propose a novel type of gravimeter based on a supersolid-like state of...

Emergent Quasicrystalline Symmetry in Light-Induced Quantum Phase Transitions

“…Furthermore, the quantum phase transition to the quasicrystalline and localized states can be attributed to the interplay between two-body contact interaction and cavity-mediated long-range interactions. Therefore, our work demonstrates that cavity QED offers a novel nondemolishing platform [79][80][81][82] for exploring the spontaneous formation and stabilization mechanisms of a quasicrystal at very low temperatures. It opens a new avenue for realizing in state-of-the-art quantum-gas-cavity systems quantum phase transitions which are accompanied by an emergent (C 8 rotational) symmetry.…”

Unraveling the Quantum Nature of Atomic Self-Ordering in a Ring Cavity

“…Note that the rotational symmetry of the Wigner functions is a direct result of the continuous translational symmetry of the system (see also Ref. [32]).…”

“…Recent theoretical [23][24][25][26][27] as well as experminental [28][29][30][31] advances push these possibilities towards spinor quantum matter based on multi-component quantum gases. A recent theoretical work [32] even predicts that the self-ordered state of a BEC in a ring cavity renders a promising platform for future high precision metrology.…”

“…Therefore, in the steady state the average order parameters Θ ± and field amplitudes α ± vanish [32,37] as the dynamics contains no process that spontaneously breaks the system's continuous symmetry.…”

Supersolid Properties of a Bose-Einstein Condensate in a Ring Resonator

“…Apart from the possibility to study the properties of the supersolid state, the realized geometry constitutes a seminal tool for a variety of future applications. Recently the supersolid state in a ring resonator was predicted to have applications in high-precission metrology [26]. In addition, the stabilization mechanism which leads to the the stable supersolid phase could be a very efficient cooling mechanism for atom clouds [22].…”