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Conditional Measurement scheme which employs linear optical elements and photon detection is the fertile ground for nonclassical state generation. We consider a simple setup that requires a coherent state and a number state as inputs of the…

Quantum Physics · Physics 2024-12-30 Devibala Esakkimuthu , Basherrudin Mahmud Ahmed A

We propose a sensing scheme for detecting weak forces that achieves Heisenberg-limited sensitivity without relying on entanglement or other non-classical resources. Our scheme utilizes coherent averaging across a chain of N optomechanical…

Quantum Physics · Physics 2026-02-10 Marta Maria Marchese , Daniel Braun , Stefan Nimmrichter , Dennis Rätzel

We investigate the superposition of coherent states, emphasizing quantum states with distinct Wigner phase-space features relevant to quantum information applications. In this study, we introduce generalized versions of the compass state,…

Quantum Physics · Physics 2025-08-26 Tan Hailin , Naeem Akhtar , Gao Xianlong

Based on N different coherent states with equal weights and phase-space rotation symmetry, we introduce N-headed incoherent superposition states (NHICSSs) and N-headed coherent superposition states (NHCSSs). These N coherent states are…

Quantum Physics · Physics 2022-06-08 Bo Lan , Xue-xiang Xu

An interferometric experiment is described that characterizes an optical cat state in a cavity mode. Our method describes how to measure the amplitude and phase of the different coherent states that make up the cat states. We show that…

Quantum Physics · Physics 2017-06-30 Marvellous Onuma-Kalu , Kae Nemoto , W. J. Munro , Robert B. Mann

Physical systems usually exhibit quantum behavior, such as superpositions and entanglement, only when they are sufficiently decoupled from a lossy environment. Paradoxically, a specially engineered interaction with the environment can…

Full coherent control and generation of superpositions of the quantum harmonic oscillator are not only of fundamental interest but are crucial for applications in quantum simulations, quantum-enhanced metrology and continuous-variable…

Quantum Physics · Physics 2024-09-06 S. Saner , O. Băzăvan , D. J. Webb , G. Araneda , D. M. Lucas , C. J. Ballance , R. Srinivas

We investigate, within the weak measurement theory, the advantages of non-classical pointer states over semi-classical ones for coherent, squeezed vacuum, and Schr\"{o}inger cat states. These states are utilized as pointer state for the…

Quantum Physics · Physics 2015-08-21 Yusuf Turek , W. Maimaiti , Yutaka Shikano , Chang-Pu Sun , M. Al-Amri

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

In recent years, there has been an increased interest in the generation of superposition of coherent states with opposite phases, the so-called photonic Schrodinger-cat states. These experiments are very challenging and so far, cats…

Quantum Physics · Physics 2015-10-28 E. Oudot , P. Sekatski , F. Fröwis , N. Gisin , N. Sangouard

We propose a state preparation protocol based on sequential measurements of a central spin coupled with a spin ensemble, and investigate the usefulness of the generated multi-spin states for quantum enhanced metrology. Our protocol is shown…

Quantum Physics · Physics 2025-01-15 T. B. Lantaño , Dayou Yang , K. M. R. Audenaert , S. F. Huelga , M. B. Plenio

We show a general relationship between a superposition of macroscopically distinct states and sensitivity in quantum metrology. Generalized cat states are defined by using an index which extracts the coherence between macroscopically…

Quantum Physics · Physics 2019-09-18 Mamiko Tatsuta , Yuichiro Matsuzaki , Akira Shimizu

We derive sampling functions for estimation of quantum state fidelity with Schr\"odinger cat-like states, which are defined as superpositions of two coherent states with opposite amplitudes. We also provide sampling functions for fidelity…

Quantum Physics · Physics 2015-06-16 Jaromir Fiurasek , Miroslav Jezek

It is often said that measuring a system's position must disturb the complementary property, momentum, by some minimum amount due to the Heisenberg uncertainty principle. Using a "weak-measurement", this disturbance can be reduced. One…

Quantum Physics · Physics 2018-11-26 G. S. Thekkadath , F. Hufnagel , J. S. Lundeen

The orthogonality of cat and displaced cat states, underlying Heisenberg limited measurement in quantum metrology, is studied in the limit of large number of states. The asymptotic expression for the corresponding state overlap function,…

Quantum Physics · Physics 2010-08-18 Raman Sharma , Prasanta K. Panigrahi

Linear superpositions of macroscopically distinct quantum states (sometimes also called Schr\"odinger cat states) are usually almost immediately reduced to a statistical mixture if exposed to the dephasing influence of a dissipative…

Quantum Physics · Physics 2007-05-23 Daniel Braun , Petr A. Braun , Fritz Haake

The Morse potential quantum system is a realistic model for studying vibrations of atoms in a diatomic molecule. This system is very close to the harmonic oscillator one. We thus propose a construction of squeezed coherent states similar to…

Mathematical Physics · Physics 2010-10-19 M. Angelova , V. Hussin

One of the peculiar features in quantum mechanics is that a superposition of macroscopically distinct states can exits. In optical system, this is highlighted by a superposition of coherent states (SCS), i.e. a superposition of classical…

Quantum Physics · Physics 2018-02-19 Shuro Izumi , Masahiro Takeoka , Kentaro Wakui , Mikio Fujiwara , Kazuhiro Ema , Masahide Sasaki

It is well-known that the precision of a phase measurement with a Mach-Zehnder interferometer employing strong (macroscopic) classic light can be greatly enhanced with the addition of a weak (microscopic) light field in a non-classical…

Quantum Physics · Physics 2022-06-06 Wenchao Ge , Kurt Jacobs , M. Suhail Zubairy

Entanglement characteristics of a pair coherent state is studied using entanglement of superposition. It is demonstrated only few states in the expansion of a pair coherent state, in a harmonic oscillator basis, contribute significantly to…

Quantum Physics · Physics 2007-08-06 Jitesh R. Bhatt , Prasanta K. Panigrahi