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In this article we present a comprehensive theoretical investigation of phonon lasing with mixed-species trapped ions, as demonstrated in [T. Behrle, Phys. Rev. Lett. 131 (2023)], employing both a semi-classical mean-field description and a…

Quantum Physics · Physics 2026-04-21 David Baur , Tanja Behrle , Ivan Rojkov , Jan Jeske , Susanne Yelin , Jonathan Home , Florentin Reiter

Single quantum emitters like atoms are well-known as non-classical light sources which can produce photons one by one at given times, with reduced intensity noise. However, the light field emitted by a single atom can exhibit much richer…

In a strongly pumped non-degenerate traveling-wave OPA, we produce two-color squeezed vacuum with up to millions of photons per pulse. Our approach to registering this macroscopic quantum state is direct detection of a large number of…

Quantum Physics · Physics 2012-04-03 Ivan N. Agafonov , Maria V. Chekhova , Gerd Leuchs

We consider squeezing of one component of the collective spin vector of an atomic ensemble inside an optical cavity. The atoms interact with a cavity mode, and the squeezing is obtained by probing the state of the light field that is…

Quantum Physics · Physics 2008-06-11 Anne E. B. Nielsen , Klaus Molmer

We have developed the full theory of a synchronously pumped type I optical parametric oscillator (SPOPO). We derive expressions for the oscillation threshold and the characteristics of the generated mode-locked signal beam. We calculate the…

Quantum Physics · Physics 2007-05-23 German J. De Valcarcel , Giuseppe Patera , Nicolas Treps , Claude Fabre

Quantum lock-in amplification raises the detection sensitivity of magnetic fields to unprecedented levels by phase-locked pumping the Zeeman levels of a single trapped atom. However, random spin precessions limits the useful detection range…

Quantum Physics · Physics 2025-12-08 Yan Zhang , Jing Zhang , Hou Ian

We present an experimentally feasible method to produce a large and tunable spin squeezing when an ensemble of many four-level atoms interacts simultaneously with a single-mode photon and classical driving lasers. Our approach is to simply…

Quantum Physics · Physics 2014-02-25 Lixian Yu , Jingtao Fan , Shiqun Zhu , Gang Chen , Suotang Jia , Franco Nori

A pair of conjugate observables, such as the quadrature amplitudes of harmonic motion, have fundamental fluctuations which are bound by the Heisenberg uncertainty relation. However, in a squeezed quantum state, fluctuations of a quantity…

Mesoscale and Nanoscale Physics · Physics 2015-12-16 J. -M. Pirkkalainen , E. Damskägg , M. Brandt , F. Massel , M. A. Sillanpää

We study the spectra of emission of a system composed by an atom, tightly confined inside a high-finesse resonator, when the atom is driven by a laser and is at steady state of the cooling dynamics induced by laser and cavity field. In…

Quantum Physics · Physics 2009-11-13 Marc Bienert , J. Mauricio Torres , Stefano Zippilli , Giovanna Morigi

Polarization squeezing is shown to occur in non-degenerate parametric amplification of coherent light and the degree of squeezing at interaction time $T$ can be as large as $1-e^{-2T}$. This gives $86.4\%$ polarization squeezing for $T=1$…

Quantum Physics · Physics 2016-12-13 Namrata Shukla , Ranjana Prakash

We present a hybrid optomechanical scheme to achieve dynamical squeezing of position quadrature of a mesoscopic mechanical oscillator, that can be externally controlled by classical fields. A membrane-in-the-middle set up is employed, in…

Quantum Physics · Physics 2016-08-24 Anil Kumar Chauhan , Asoka Biswas

High-quality superconducting oscillators have been successfully used for quantum control and readout devices in conjunction with superconducting qubits. Also, it is well known that squeezed states can improve the accuracy of measurements to…

Superconductivity · Physics 2009-11-13 A. M. Zagoskin , E. Il'ichev , M. W. McCutcheon , Jeff Young , Franco Nori

Number state filtered coherent states are a class of nonclassical states obtained by removing one or more number states from a coherent state. Phase sensitivity of an interferometer is enhanced if these nonclassical states are used as input…

Quantum Physics · Physics 2020-01-09 Nilakantha Meher , S. Sivakumar

We analyze the creation of spin squeezed atomic ensembles by simultaneous dispersive interactions with several optical frequencies. A judicious choice of optical parameters enables optimization of an interferometric detection scheme that…

Quantum Physics · Physics 2009-05-14 M. Saffman , D. Oblak , J. Appel , E. S. Polzik

We have previously shown that quantum-enhanced atom interferometry can be achieved by mapping the quantum state of squeezed optical vacuum to one of the atomic inputs via a beamsplitter-like process [Phys.~Rev.~A \textbf{90}, 063630…

Quantum Physics · Physics 2015-04-01 Behnam Tonekaboni , Simon A. Haine , Stuart S. Szigeti

Quantum entanglement can provide enhanced precision beyond standard quantum limit (SQL), the highest precision achievable with classical means. It remains challenging, however, to observe large enhancement limited by the experimental…

Quantum Gases · Physics 2022-12-20 Tian-Wei Mao , Qi Liu , Xin-Wei Li , Jia-Hao Cao , Feng Chen , Wen-Xin Xu , Meng Khoon Tey , Yi-Xiao Huang , Li You

The interaction of a quantized field with three-level atoms in $\Lambda$ configuration inside a two mode cavity is analyzed. We calculate the stationary quadrature noise spectrum of the field outside the cavity in the case where the input…

Quantum Physics · Physics 2007-05-23 P. Barberis-Blostein

The intensity buildup of light inside a lossy microring resonator can be used to enhance the generation of squeezed states via spontaneous parametric downconversion (SPDC). In this work, we model the generation of squeezed light in a…

Optics · Physics 2020-08-19 Colin Vendromin , Marc M. Dignam

The degree of polarization of a quantum state can be defined as its Hilbert-Schmidt distance to the set of unpolarized states. We demonstrate that the states optimizing this degree for a fixed average number of photons $\bar{N}$ present a…

Quantum Physics · Physics 2008-07-25 L. L. Sanchez-Soto , E. C. Yustas , G. Bjork , A. B. Klimov

We investigate the squeezing of ultrashort pulses using self-induced transparency in a mercury-filled hollow-core photonic crystal fiber. Our focus is on quadrature squeezing at low mercury vapor pressures, with atoms near resonance on the…

Quantum Physics · Physics 2025-09-01 M. S. Najafabadi , J. F. Corney , L. L. Sánchez-Soto , N. Y. Joly , G. Leuchs