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Related papers: Nature abhors macroscopic superpositions

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Schr\"{o}dinger cat states of levitated masses have several applications in sensing and, offer an avenue to explore the fundamental nature -- classical vs nonclassical -- of gravity, eg, through gravitationally induced entanglement (GIE).…

Quantum Physics · Physics 2024-08-23 Lorenzo Braccini , Alessio Serafini , Sougato Bose

During the past decade, the experimental development of being able to create ever larger and heavier quantum superpositions has brought the discussion of the connection between microscopic quantum mechanics and macroscopic classical physics…

Quantum Physics · Physics 2010-04-29 Jasper van Wezel

We propose a measure for the "size" of a Schroedinger cat state, i.e. a quantum superposition of two many-body states with (supposedly) macroscopically distinct properties, by counting how many single-particle operations are needed to map…

Quantum Physics · Physics 2008-07-22 Florian Marquardt , Benjamin Abel , Jan von Delft

We suggest a scheme to generate a macroscopic superposition state (Schrodinger cat state) of a free-propagating optical field using a beam splitter, homodyne measurement and a very small Kerr nonlinear effect. Our scheme makes it possible…

Quantum Physics · Physics 2009-11-10 H. Jeong , M. S. Kim , T. C. Ralph , B. S. Ham

Classical linear wave superposition produces the appearance of interference. This observation can be interpreted in two equivalent ways: one can assume that interference is an illusion because input components remain unperturbed, or that…

Quantum Physics · Physics 2013-07-17 Ghenadie N. Mardari , James A. Greenwood

We reconsider a well known problem of quantum theory, i.e. the so called measurement (or macro-objectification) problem, and we rederive the fact that it gives rise to serious problems of interpretation. The novelty of our approach derives…

Quantum Physics · Physics 2009-11-06 Angelo Bassi , GianCarlo Ghirardi

Theory and experiment both demonstrate that an entangled quantum state of two subsystems is neither a superposition of states of its subsystems nor a superposition of composite states but rather a coherent superposition of nonlocal…

Quantum Physics · Physics 2022-06-14 Art Hobson

We study the dissipative dynamics of deformed coherent states superposition. We find that such kind of superposition can be more robust against decoherence than the usual Schrodinger cat states.

Quantum Physics · Physics 2009-11-07 Stefano Mancini , Vladimir I. Man'ko

Creating a massive spatial quantum superposition, such as the Schr\"odinger cat state, where the mass and the superposition size within the range $10^{-19}-10^{-14}$ kg and $\Delta x \sim 10~{\rm nm}-100~\mu {\rm m}$, is a challenging task.…

Quantum Physics · Physics 2023-12-04 Run Zhou , Ryan J. Marshman , Sougato Bose , Anupam Mazumdar

The ability of matter to be superposed at two different locations while being intrinsically connected by a quantum phase is among the most counterintuitive predictions of quantum physics. While such superpositions have been created for a…

Quantum Physics · Physics 2016-04-13 D. Kienzler , C. Flühmann , V. Negnevitsky , H. -Y. Lo , M. Marinelli , D. Nadlinger , J. P. Home

Selected issues of the concept of spontaneous collapse are discussed, with the emphasis on the gravity-related model. We point out that without spontaneous collapses the Schr\"odinger cat states would macroscopically violate the standard…

Quantum Physics · Physics 2014-11-19 Lajos Diósi

Quantum gravity is expected to contain descriptions of semiclassical spacetime geometries in quantum superpositions. To date, no framework for modelling such superpositions has been devised. Here, we provide a new phenomenological…

General Relativity and Quantum Cosmology · Physics 2021-05-11 Joshua Foo , Robert B. Mann , Magdalena Zych

We show how macroscopically distinct quantum superposition states (Schroedinger cat states) may be used as logical qubit encodings for the correction of spontaneous emission errors. Spontaneous emission causes a bit flip error which is…

Quantum Physics · Physics 2009-10-31 P. T. Cochrane , G. J. Milburn , W. J. Munro

By associating a binary signal with the relativistic worldline of a particle, a binary form of the phase of non-relativistic wavefunctions is naturally produced by time dilation. An analog of superposition also appears as a Lorentz…

Quantum Physics · Physics 2017-09-08 G. N. Ord

We present several examples where prominent quantum properties are transferred from a microscopic superposition to thermal states at high temperatures. Our work is motivated by an analogy of Schrodinger's cat paradox, where the state…

Quantum Physics · Physics 2007-05-23 Hyunseok Jeong , Timothy C. Ralph

We investigate the quantum properties of superpositions of oppositely squeezed states, which can be regarded as Schrodinger cat states. Compared with conventional coherent-state cat states, these states exhibit distinct photon-number…

Quantum Physics · Physics 2025-11-06 Hiroo Azuma , William J. Munro , Kae Nemoto

The principle of linear superposition is a hallmark of quantum theory. It has been confirmed experimentally for photons, electrons, neutrons, atoms, for molecules having masses up to ten thousand amu, and also in collective states such as…

Quantum Physics · Physics 2012-12-04 Angelo Bassi , Tejinder P. Singh , Hendrik Ulbricht

Massive objects in spatial superposition may provide insights into the interplay between quantum mechanics and gravity. Cold atomic interferometers offer a promising platform due to extended matter-wave coherence times and precise…

Quantum Gases · Physics 2026-05-13 Han Zhang , Yong-Kui Wang , Yi Zheng , Hai-Tao Bai , Bing Yang

Schr\"odinger cat states, which are superpositions of macroscopically distinct states, are potentially critical resources for upcoming quantum information technologies. In this paper, we introduce a scheme to generate entangled…

High Energy Physics - Theory · Physics 2024-08-14 Partha Nandi , Nandita Debnath , Subhajit Kala , A. S. Majumdar

The observed general time-asymmetric behavior of macroscopic systems -- embodied in the second law of thermodynamics -- arises naturally from time-symmetric microscopic laws due to the great disparity between macro and micro-scales. More…

Condensed Matter · Physics 2007-05-23 Joel L. Lebowitz