Abstract The quantization of gravity is widely believed to result in gravitons – particles discrete energy that form gravitational waves. But their detection has so far been considered impossible. Here we show signatures single graviton exchange can be observed laboratory experiments. We stimulated and spontaneous single-graviton processes become relevant for massive quantum acoustic resonators absorption resolved through continuous sensing jumps. analyze the feasibility observing quanta...

Abstract We propose a multi-mode bar consisting of mass elements decreasing size for the implementation gravitational version photo-electric effect through stimulated absorption up to kHz gravitons from binary neutron star merger and post-merger. find that detector has normal modes retain coupling strength wave largest mass-element, while only having an effective comparable smallest element. This allows have graviton rates due tonne-scale mass, single process in mode could be resolved energy...

The theory of general relativity predicts the existence closed time-like curves (CTCs), which theoretically would allow an observer to travel back in time and interact with their past self. This raises question whether this could create a grandfather paradox, interacts such way prevent own travel. Previous research has proposed framework for deterministic, reversible, dynamics compatible non-trivial travel, where observers distinct regions spacetime can perform arbitrary local operations no...

Abstract Theories of spontaneous wavefunction collapse offer an explanation the possible breakdown quantum mechanics for macroscopic systems. However, challenge resolving predicted signatures above background noise has precluded conclusive tests. Here, we propose to overcome this using control and measurement a superconducting qubit coupled mechanical resonator. We show that can amplify weak signals from collapse-induced heating simultaneously suppress noise, initializing close its ground...

The authors study quantum effects resulting from mass-energy equivalence using ultracold neutrons that are confined gravitationally by considering a correction to the neutron's mass due neutron spin in presence of an external magnetic field. show additional weight treatment will cause small shift eigenenergies and eigenstates, which could provide signatures interferometric experiment.

We propose a multi-mode bar consisting of mass elements decreasing size for the direct detection stimulated absorption up to kHz gravitons from neutron star merger and post-merger. find that detector has normal modes retain coupling strength gravitational wave largest mass-element, while only having an effective comparable smallest element. This allows have graviton rates due tonne-scale mass, single process in mode could be resolved through energy measurements mass-element in-principle...

In a recent work we showed that the detection of exchange single graviton between massive quantum resonator and gravitational wave can be achieved. Key to this ability are experimental progress in preparing measuring resonators regime, correlation with independent LIGO detections waves induce stimulated absorption. But do single-graviton processes imply quantization gravity? Here analyze question make historic analogy early days theory. We discuss what ways such experiments indeed probe key...

The photo-electric effect was a historic milestone in the development of quantum theory, revealing first evidence discrete energy electromagnetic field through hallmark signatures such as threshold frequency, intensity-independent transfer, and near instantaneous ejection photo-electrons. In this work, we revisit lens semi-classical, quantum, neo-classical models to explore their implications on conservation photon exchange. We extend analysis include gravito-phononic modelling transfer...

The quantization of gravity is widely believed to result in gravitons -- particles discrete energy that form gravitational waves. But their detection has so far been considered impossible. Here we show signatures single graviton exchange can be observed laboratory experiments. We stimulated and spontaneous single-graviton processes become relevant for massive quantum acoustic resonators absorption resolved through continuous sensing jumps. analyze the feasibility observing quanta between...

Gravitationally bound neutrons have become an important tool in the experimental searches for new physics, such as modifications to Newton's force or candidates dark matter particles. Here we include relativistic effects of mass-energy equivalence into model gravitationally neutrons. Specifically, investigate a correction neutron's Hamiltonian due presence external magnetic field. We show that additional weight will cause small shift eigenenergies and eigenstates, examine how this would...

Theories of spontaneous wavefunction collapse offer an explanation the possible breakdown quantum mechanics for macroscopic systems. However, challenge resolving predicted signatures above background noise has precluded conclusive tests. Here, we propose to overcome this using a superconducting qubit precisely readout collapse-induced heating mechanical resonator. We show that ability strongly couple resonator can enable both fast measurements and initialization close its ground state....