@article{Gaona-Reyes2025,

title = {Theoretical limits of protocols for distinguishing different unravelings},

author = {J. L. Gaona-Reyes and D. G. A. Altamura and A. Bassi},

doi = {10.1103/6qnt-t3wl},

issn = {2643-1564},

year  = {2025},

date = {2025-12-15},

journal = {Phys. Rev. Research},

volume = {7},

number = {4},

publisher = {American Physical Society (APS)},

abstract = {<jats:p>Stochastic unravelings of Lindblad-type master equations, such as stochastic Schrödinger equations, provide powerful tools to model open quantum systems and continuous measurement processes. The same master equation can be unraveled in different ways; while these unravelings differ at the level of quantum trajectories, by construction they all yield the same averaged dynamics for the density operator. A recent question of both foundational and practical relevance is whether such unravelings can be operationally distinguished, given that certain nonlinear quantities—such as covariances and higher-order moments of conditional expectation values—are unraveling dependent. We show that these quantities cannot be accessed unless the measurement scheme (i.e., the unraveling) is known in advance. This renders any operational protocol to distinguish unravelings fundamentally unfeasible. We further establish that assuming access to such nonlinear quantities without prior knowledge of the unraveling would enable superluminal signaling, violating relativistic causality.</jats:p>},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Piccione2025d,

title = {Hybrid classical-quantum Newtonian gravity with stable vacuum},

author = {Nicolò Piccione and Angelo Bassi},

doi = {10.1088/1361-6382/ae1540},

issn = {1361-6382},

year  = {2025},

date = {2025-11-21},

journal = {Class. Quantum Grav.},

volume = {42},

number = {22},

publisher = {IOP Publishing},

abstract = {Abstract

                  We investigate the gravitational Poissonian spontaneous localization (GPSL) model, a hybrid classical-quantum model in which classical Newtonian gravity emerges from stochastic collapses of the mass density operator, and consistently couples to quantum matter. Unlike models based on continuous weak measurement schemes, we show that GPSL ensures vacuum stability; this, together with its applicability to identical particles and fields, makes it a promising candidate for a relativistic generalization. We analyze the model’s general properties, and compare its predictions with those based on continuous weak measurement schemes. Notably, here the gravitational feedback enters entirely through the non-Hermitian jump operators, without modifying the unitary part of the dynamics. We show that this leads to a short-range gravitational back-reaction and permits decoherence rates below those of any model based on continuous weak measurement schemes. We provide explicit examples, including the dynamics of a single particle and a rigid sphere, to illustrate the distinctive phenomenology of the model. Finally, we discuss the experimental testability of GPSL, highlighting both interferometric and non-interferometric strategies to constrain its parameters and distinguish it from competing models.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Cromb2025,

title = {Creation of a black hole bomb instability in an electromagnetic system},

author = {M. Cromb and M.C. Braidotti and A. Vinante and D. Faccio and H. Ulbricht},

doi = {10.1126/sciadv.adz4595},

issn = {2375-2548},

year  = {2025},

date = {2025-11-07},

journal = {Sci. Adv.},

volume = {11},

number = {45},

publisher = {American Association for the Advancement of Science (AAAS)},

abstract = {The amplification and generation of electromagnetic radiation by a rotating metallic or lossy cylinder, first proposed by Zel’dovich in the 1970s, is closely linked to quantum friction, energy extraction from rotating black holes, and runaway mechanisms such as black hole bombs. Although advances such as acoustic analogs of the Zel’dovich effect and the observation of negative resistance in low-frequency electromagnetic models have been reported, genuine positive signal gain, spontaneous emission of electromagnetic waves, and runaway amplification have not previously been verified. Here, we provide the first experimental demonstration that a mechanically rotating metallic cylinder acts as an amplifier of a rotating electromagnetic field mode. Moreover, when combined with a low-loss resonator, the system becomes unstable and operates as a generator seeded only by noise. The exponential runaway amplification of spontaneously generated electromagnetic modes is observed, establishing the electromagnetic analog of the Press-Teukolsky black hole bomb and paving the way to experimental tests of quantum friction from vacuum fluctuations.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Homans2025,

title = {An experimental platform for levitated mechanics in space},

author = {Jack Homans and Elliot Simcox and Jakub Wardak and Laura da Palma Barbara and Tim M Fuchs and Rafael Mufato and Florence Concepcion and Andrei Dragomir and Christian Vogt and Peter Nisbet-Jones and Christopher Bridges and Hendrik Ulbricht},

doi = {10.1088/2058-9565/ade624},

issn = {2058-9565},

year  = {2025},

date = {2025-10-01},

journal = {Quantum Sci. Technol.},

volume = {10},

number = {3},

publisher = {IOP Publishing},

abstract = {Abstract

               Conducting experiments in extreme conditions has long been the aim of the levitated mechanics field, as it allows for the investigation of new fundamental physics phenomena. Sending these experiments into the micro-g environment of space has been one such milestone, with multiple proposals calling for such a platform. At the same time, levitated sensors have demonstrated a high sensitivity to external stimuli, such as electric, magnetic and gravitational forces, which will only improve in low-vibrational conditions. This paper describes the development of a technology demonstrator for optical and magnetic trapping experiments in space. Our payload represents the first concrete step towards future missions with aims of probing fundamental physical questions: matter-wave interferometry of nanoparticles to probe the limits of macroscopic quantum mechanics, detection of Dark Matter candidates and gravitational waves to test physics beyond the Standard Model, and accelerometry for Earth-observation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}