Near-field interferometry of a free-falling nanoparticle from a point-like source

Abstract

Matter-wave interferometry performed with massive objects elucidates their wave nature and thus tests the quantum superposition principle at large scales. Whereas standard quantum theory places no limit on particle size, alternative, yet untested theories-conceived to explain the apparent quantum to classical transition-forbid macroscopic superpositions. Here we propose an interferometer with a levitated, optically cooled and then free-falling silicon nanoparticle in the mass range of one million atomic mass units, delocalized over 4150 nm. The scheme employs the near-field Talbot effect with a single standing-wave laser pulse as a phase grating. Our analysis, which accounts for all relevant sources of decoherence, indicates that this is a viable route towards macroscopic high-mass superpositions using available technology.

Distinguishing decoherence from alternative quantum theories by dynamical decoupling

“…This is a different parameter regime compared to tests using macroscopic superpositions [16][17][18][19], where AQT predict stronger effects but dynamical decoupling is challenging (see, however, [20]). …”

Displacemon Electromechanics: How to Detect Quantum Interference in a Nanomechanical Resonator

“…Although the nanotube resonator considered here does not have enough mass to seriously challenge the interesting parameter regime of objective collapse theories, a similar protocol could be extended to more massive objects still well within the range of nanomechanics. This research direction could allow for testing specific theories of quantum collapse [8], as an alternative to proposals based on single-photon optomechanics [9] or levitated nanoparticles [11,72]. Multiple resonators coupled to the same qubit (such as the pair of nanotube junctions in Fig.…”

“…The ability to create unambiguous superpositions on a mesoscopic scale would allow tests of quantum collapse theories and gravitational decoherence [3][4][5][6][7], ultimately addressing experimentally the question of why we fail to see superpositions in everyday life [8]. This has inspired numerous challenging proposals to detect interference of larger particles [9][10][11] via optomechanical coupling [12], or by using levitated nanodiamonds [13,14].…”

Wigner Function Reconstruction in Levitated Optomechanics

“…In other words, extremely high quality factors of the mechanical oscillation of the particle in the trap can be achieved [13,14]. As a consequence, levitated systems are promising for manifold studies and applications such as macroscopic quantum superpositions [13,15,16], force sensing [17,18], and single particle thermodynamics [19][20][21]. Development in levitated optomechanics experiments over the last ve years or so, has resulted in the successful demonstration of cooling [22][23][24][25] to less than 100 phonons and squashing [26] the cm motion of the particle.…”