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We propose periodically-modulated entangled states of light and show that they can be generated in two experimentally feasible schemes of nondegenerate optical parametric oscillator (NOPO): (i) driven by continuously modulated pump field;…

Quantum Physics · Physics 2007-05-23 H. H. Adamyan , G. Yu. Kryuchkyan

Real quantum systems couple to their environment and lose their intrinsic quantum nature through the process known as decoherence. Here we present a method for minimizing decoherence by making it energetically unfavorable. We present a…

Quantum Physics · Physics 2009-11-06 D. Bacon , K. R. Brown , K. B. Whaley

We implement dynamical decoupling techniques to mitigate noise and enhance the lifetime of an entangled state that is formed in a superconducting flux qubit coupled to a microscopic two-level system. By rapidly changing the qubit's…

We introduce a high-fidelity technique for coherent control of three-state quantum systems, which combines two popular control tools --- stimulated Raman adiabatic passage (STIRAP) and composite pulses. By using composite sequences of pairs…

Quantum Physics · Physics 2013-06-05 Boyan T. Torosov , Nikolay V. Vitanov

In this work, we exploit the idea of composite pulses to achieve robust population inversion in a three-level quantum system. The scheme is based on the modulation of the coupling strength, while the other physical parameters remain…

Quantum Physics · Physics 2022-04-11 Cheng Zhang , Yang Liu , Zhi-Cheng Shi , Jie Song , Yan Xia , Shi-Biao Zheng

We propose a general scheme for dissipatively preparing arbitrary pure quantum states on a multipartite qubit register in a finite number of basic control blocks. Our "splitting-subspace" approach relies on control resources that are…

Quantum Physics · Physics 2013-11-19 Giacomo Baggio , Francesco Ticozzi , Lorenza Viola

Ubiquitous in quantum computing is the step to encode data into a quantum state. This process is called quantum state preparation, and its complexity for non-structured data is exponential on the number of qubits. Several works address this…

Quantum Physics · Physics 2023-07-28 Israel F. Araujo , Carsten Blank , Ismael C. S. Araújo , Adenilton J. da Silva

Practical schemes for creation of multi-mode squeezed (entangled) states of atomic ensembles located inside a high-Q ring cavity are discussed. It is assumed that the cavity is composed of two degenerate mutually counter-propagating modes…

Quantum Physics · Physics 2015-05-13 Gao-xiang Li , Zbigniew Ficek

Inspired by recent advances in the manipulation of superconducting circuits coupled to mechanical modes in the quantum regime, we propose a protocol for generating superpositions of orthogonally squeezed states in a quantum harmonic…

Quantum Physics · Physics 2026-03-05 Marius K. Hope , Jonas Lidal , Francesco Massel

We use the invariant-based inverse engineering subject to the quasiadiabatic condition to produce robust and high fidelity coherent superposition of quantum states. The inverse engineering provides shortcuts to the desired quantum-state…

Quantum Physics · Physics 2017-09-12 Yen-Huang Liu , Shuo-Yen Tseng

We propose an experimentally accessible procedure for conditional preparation of highly non-classical states of collective spin of an atomic ensemble. The quantum state engineering is based on a combination of QND interaction between atoms…

Quantum Physics · Physics 2013-05-29 Karel Lemr , Jaromir Fiurasek

We investigate the possibility of using a dissipative process to prepare a quantum system in a desired state. We derive for any multipartite pure state a dissipative process for which this state is the unique stationary state and solve the…

Quantum Physics · Physics 2012-09-12 B. Kraus , H. P. Büchler , S. Diehl , A. Kantian , A. Micheli , P. Zoller

We study a classical $\Lambda$-type three-level system based on three high-$Q$ micromechanical beam resonators embedded in a gradient electric field. By modulating the strength of the field at the difference frequency between adjacent beam…

It is known that protocols based on weak measurements can be used to steer quantum systems into pre-designated pure states. Here we show that weak-measurement-based steering protocols can be harnessed for on-demand engineering of…

Quantum Physics · Physics 2020-10-28 Parveen Kumar , Kyrylo Snizhko , Yuval Gefen

The interaction of a three level Rydberg atom of Lambda-type with a single mode optical field in far off-resonant and at large detuning regimes can be described by an effective degenerate Raman model, where the atomic state can be treated…

Quantum Physics · Physics 2011-10-10 Thiago Prudencio

We present a new robust decoupling scheme suitable for levels with either half integer or integer angular momentum states. Through continuous dynamical decoupling techniques, we create a protected qubit subspace, utilizing a multi-state…

Quantum Physics · Physics 2014-04-29 N. Aharon , M. Drewsen , A. Retzker

A scheme is proposed here to achieve swapping and entangling of photonic and atomic qubits with high fidelity. The mechanism is based on the scattering of a single photon from a $\Lambda$-type three-level atom. The evolution of the coupled…

Quantum Physics · Physics 2007-05-23 T. W. Chen , C. K. Law , P. T. Leung

We propose a scheme of optical pumping by which a system of atoms coupled to harmonic oscillators is driven to an entangled steady state through the atomic spontaneous emission. It is shown that the optical pumping can be tailored so that…

Quantum Physics · Physics 2011-01-18 Jaeyoon Cho , Sougato Bose , M. S. Kim

We demonstrate an unseeded, multimode four-wave mixing process in hot $^{85}$Rb vapor, using two pump beams of the same frequency that cross at a small angle. This results in the simultaneous fulfillment of multiple phase-matching…

Quantum Physics · Physics 2018-08-01 Erin M. Knutson , Jon D. Swaim , Sara Wyllie , Ryan T. Glasser

We propose a probabilistic scheme to prepare a maximally entangled state between a pair of two-level atoms inside a leaking cavity, without requiring precise time-controlling of the system evolution and initial atomic state. We show that…

Quantum Physics · Physics 2013-10-24 D. Z. Rossatto , C. J. Villas-Boas