Understanding gravity in the framework of quantum mechanics is one great challenges modern physics. However, lack empirical evidence has lead to a debate on whether entity. Despite varied proposed probes for gravity, it fair say that there are no feasible ideas yet test its coherent behavior directly laboratory experiment. Here, we introduce an idea such based principle two objects cannot be entangled without mediator. We show despite weakness phase evolution induced by gravitational...

This paper points out the importance of quantum nature gravitational interaction with matter in a linearized theory gravity induced entanglement masses. We will show how entangles steady states closed system (eigenstates) two test masses placed harmonic traps, and such matter-matter emerges from an underlying field. rely upon perturbation highlighting critical assumptions for generating showing that classical field does not render entanglement. consider distinct examples: one where...

Levitated optomechanics is showing potential for precise force measurements. Here, we report a case study to show experimentally the capacity of such sensor, using an electric field as tool detect Coulomb applied onto levitated nanosphere. We observe spatial displacement up 6.6 nm nanosphere by imposing DC field. further apply AC and demonstrate resonant enhancement sensing when driving frequency, ωAC, frequency mechanical oscillator, ω0, converge. directly measure 3.0 ± 1.5 × 10–20 N with...

The deflection of light in the gravitational field Sun is one most fundamental consequences for general relativity as well its classical tests first performed by Eddington a century ago. However, despite center stage role modern physics, no experiment has tested it an ostensibly quantum regime where both matter and exhibit nonclassical features. This paper shows that interaction which gives rise to light-bending also induces photon-matter entanglement long gravity are treated at par with...

The Einstein equivalence principle is based on the equality of gravitational and inertial mass, which has led to universality a free-fall concept. been extremely well tested so far with great precision. However, all these tests corresponding arguments are classical setup where notion position velocity mass associated value as opposed quantum entities.Here, we provide simple protocol creating large spatial superposition states in laboratory test regime both matter gravity treated at par...

Matter-wave interferometry with nanoparticles will enable the development of quantum sensors capable probing ultraweak fields unprecedented applications for fundamental physics. The high sensitivity such devices, however. makes them susceptible to several noise and decoherence sources and, as such, can operate only when sufficient isolation from environment is achieved. It thus imperative model characterize interaction estimate its deleterious effects. This paper aim study matter-wave...

We investigate experimentally the dynamics of a nonspherical levitated nanoparticle in vacuum. In addition to translation and rotation motion, we observe light torque-induced precession nutation trapped particle. provide theoretical model, which numerically simulate from derive approximate expressions for motional frequencies. Both simulation find good agreement with experiments. measure torque 1.9±0.5×10^{-23} N m at 1×10^{-1} mbar, an estimated sensitivity 3.6±1.1×10^{-31} m/sqrt[Hz]...

Starting from an idea of S. L. Adler [in Quantum Nonlocality and Reality: 50 Years Bell's Theorem, edited by M. Bell Gao (Cambridge University Press, Cambridge, England 2016)], we develop a novel model gravity induced spontaneous wave function collapse. The collapse is driven complex stochastic fluctuations the spacetime metric. After deriving fundamental equations, prove amplification mechanism, two most important features consistent model. Under reasonable simplifying assumptions,...

Matter-wave interferometers have fundamental applications for gravity experiments such as testing the equivalence principle and quantum nature of gravity. In addition, matter-wave can be used sensors to measure local gravitational acceleration caused by external massive moving objects, thus lending itself technological applications. this paper, we will establish a three-dimensional model describe gradient signal from an object, theoretically investigate achievable sensitivities using...

We consider a quantum harmonic oscillator coupled with graviton bath. discuss the loss of coherence in matter sector due to matter-graviton vertex interaction, which leads provided that matter-wave system is allowed gravitons by kinematics. Working quantum-field-theory framework, we obtain master equation tracing away gravitational field at leading order <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mo>∼</a:mo><a:mi mathvariant="script">O</a:mi><a:mo...

Collapse models, proposed to explain the absence of quantum superpositions at macroscopic scales, generically predict existence random forces on a massive object. Here, detection levitated particle motion is explored though three different approaches based an optical cavity, tweezer, and electrical readout exploiting SQUID. These are analyzed compared, advantages, drawbacks, technical challenges assessed.

Although quantum physics is well understood in inertial reference frames (flat spacetime), a current challenge the search for experimental evidence of non-trivial or unexpected behaviour systems non-inertial frames. Here, we present novel test mechanics frame: consider Hong-Ou-Mandel (HOM) interference on rotating platform and study effect uniform rotation distinguishability photons. Both theory experiments show that rotational motion induces relative delay photon arrival times at exit...

Abstract One of the outstanding questions in modern physics is how to test whether gravity classical or quantum a laboratory. Recently there has been proposal nature by creating superpositions two nearby neutral masses, close enough that can entangle systems, but still sufficiently far away all other known Standard Model interactions remain negligible. However, preparing superposition states mass (the light system) requires vicinity laboratory apparatus heavy system). We will suppose such...

The salient feature of both classical and quantum gravity is its universal attractive character. However, less known about the behavior build-up correlations when systems interact via graviton exchange. In this work, we show that can remain strongly suppressed for certain choices parameters even considering two adjacent in delocalized states. Using framework linearized with post-Newtonian contributions, find there are special values delocalization where gravitationally induced entanglement...

We present a simple derivation of the interference pattern in matter-wave interferometry as predicted by class master equations, using density matrix formalism. apply obtained formulae to most relevant collapse models, namely Ghirardi-Rimini-Weber (GRW) model, continuous spontaneous localization (CSL) model together with its dissipative (dCSL) and non-markovian generalizations (cCSL), quantum mechanics universal position (QMUPL) Di\'{o}si-Penrose (DP) model. discuss separability models...

We demonstrate that a Kalman filter applied to estimate the position of an optically levitated nanoparticle, and operated in real-time within field programmable gate array, is sufficient perform closed-loop parametric feedback cooling center-of-mass motion sub-Kelvin temperatures. The translational along optical axis trapped nanoparticle has been cooled by 3 orders magnitude, from temperature 300 K $162\ifmmode\pm\else\textpm\fi{}15$ mK.

The modification by noninertial motion of the photon bunching properties an entangled biphoton state is demonstrated. Sagnac interferometers are added to both arms a Hong-Ou-Mandel (HOM) interferometer that mounted on mechanically rotating platform. As platform rotation speed increased, HOM interference dips transform into peaks, indicating photons pass from perfectly indistinguishable (bosonic behavior) distinguishable antibunching (fermionic behavior).

We examine a macroscopic system in quantum superposition of two spatially separated localized states as detector for stream weakly interacting relativistic particles. do this using the explicit example neutrinos with $\mathrm{MeV}$-scale energy scattering from solid object via neutral-current neutrino-nucleus scattering. Presuming (anti)neutrino source to be nuclear fission reactor, we utilize estimated flux and coherent elastic cross section constrain spatial separation...

Many phenomena and fundamental predictions, ranging from Hawking radiation to the early evolution of Universe rely on interplay between quantum mechanics gravity or more generally, in curved spacetimes. However, our understanding is hindered by lack experiments that actually allow us probe spacetime a repeatable accessible way. Here we propose an experimental scheme for photon prepared path superposition state across two rotating Sagnac interferometers have different diameters thus represent...

Matter-wave interferometers with microparticles will enable the next generation of quantum sensors to probe minute phase information. Therefore, estimating loss coherence and degree entanglement degradation for such is essential. In this paper, we provide a noise analysis in frequency-space focusing on electromagnetic sources dephasing. We assume that our matter-wave interferometer has residual charge or dipole which can interact neighboring particle ambience. investigate dephasing due...

Motivated by the current interest in employing quantum sensors on Earth and space to conduct searches for new physics, we provide a perspective suitability of large-mass levitated optomechanical systems observing dark matter signatures. We discuss conservative approaches recoil detection through spectral analysis coherently scattered light, enhancements directional effects due cross-correlation densities, possibility using superpositions mesoscopic test particles measure rare events.