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Time domain terahertz spectroscopy typically uses mechanical delay stages that inherently suffer from non-uniform sampling positions. We review, simulate, and experimentally test the ability of corrective cubic spline and Shannon…

Optics · Physics 2019-03-20 A. M. Potts , T. T. Mai , M. T. Warren , R. Valdés Aguilar

Quantum information encoded into superposition of coherent states is an illustrative representative of practical applications of macroscopic quantum coherence possessing. However, these states are very sensitive to energy loss, losing their…

We discuss quantum evolution of a decaying state in relation to a recent experiment of Katz et al. Based on exact analytical and numerical solutions of a simple model, we identify a regime where qubit retains coherence over a finite time…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Leonid P. Pryadko , Alexander N. Korotkov

We propose a resource-efficient error-rejecting entangled-state analyzer for polarization-encoded multiphoton systems. Our analyzer is based on two single-photon quantum-nondemolition detectors, where each of them is implemented with a…

Quantum Physics · Physics 2019-11-13 Tao Li , Adam Miranowicz , Keyu Xia , Franco Nori

Multiqubit Greenberger-Horne-Zeilinger (GHZ) state preparation is demonstrated on two to eight qubits in the chain of ten $^{171}Yb^+$ ions in the linear Paul trap with a sequence of single-qubit and two-qubit operations and pulsed…

A protocol for generating Greenberger-Horne-Zeilinger states in a system of $N$ coupled qubits is proposed. The Hamiltonian model assumes $N$-wise interactions between the $N$ qubits and the presence of a controllable time-dependent field…

We propose a method to perform precision measurements of the interaction parameters in systems of N ultra-cold spin 1/2 atoms. The spectroscopy is realized by first creating a coherent spin superposition of the two relevant internal states…

Other Condensed Matter · Physics 2009-11-13 A. M. Rey , L. Jiang , M. D. Lukin

To manufacture faster electron devices, the industry has entered into the nanoscale dimensions and Terahertz (THz) working frequencies. The discrete nature of the few electrons present simultaneously in the active region of ultra-small…

Mesoscale and Nanoscale Physics · Physics 2024-02-13 Enrique Colomés , Javier Mateos , Tomás González , Xavier Oriols

The decoherence phenomenon inevitably exists in quantum computing processes. Consequently, dynamic suppression of decoherence for instance via dynamical decoupling, quantum error correction codes (QECC) etc. is crucial in accurately…

Quantum Physics · Physics 2023-11-30 Lian-Ao Wu

Non-classical resources enable measurements to achieve a precision that exceeds the limits predicted by the central limit theorem. However, environmental noise arising from system-environment interactions severely limits the performance of…

Quantum Physics · Physics 2025-01-06 Bakmou Lahcen , Ke Zeng , Yu Jiang , Kok Chuan Tan

Generating entanglement deterministically at a capacity-approaching rate is critical for next-generation quantum networks. We propose weak-coherent-state-assisted protocols that can generate entanglement near-deterministically between…

Quantum Physics · Physics 2025-05-06 Chaohan Cui , Prajit Dhara , Saikat Guha

The ability to preserve multipartite entanglement in noisy environments is central to advancing quantum information processing. In this work, we develop a semiclassical theoretical model of three entangled qubits exposed to local Markov…

Quantum Physics · Physics 2025-11-14 Stephen Brockerhoff , Brittany Corn-Agostini

We embarked upon the task of experimental protection of different classes of tripartite entangled states, namely the maximally entangled GHZ and W states and the ${\rm W \bar{W}}$ state, using dynamical decoupling. The states were created…

Quantum Physics · Physics 2018-02-07 Harpreet Singh , Arvind , Kavita Dorai

Long qubit coherence and efficient atom-photon coupling are essential for advanced applications in quantum communication. One technique to maintain coherence is dynamical decoupling, where a periodic sequence of refocusing pulses is…

Quantum Physics · Physics 2021-02-02 Chang Hoong Chow , Boon Long Ng , Christian Kurtsiefer

It is known from Bell's theorem that quantum predictions for some entangled states cannot be mimicked using local hidden variable (LHV) models. From a computer science perspective, LHV models may be interpreted as classical computers…

Quantum Physics · Physics 2014-10-08 T. K. Chuan , T. Paterek

The prototypical Schr\"{o}dinger cat state, i.e., an initial state corresponding to two widely separated Gaussian wave packets, is considered. The decoherence time is calculated solely within the framework of elementary quantum mechanics…

Quantum Physics · Physics 2009-11-10 G. W. Ford , R. F. O'Connell

The decoherence of a qubit due to a classical non-Gaussian noise with correlation time longer than the decoherence time is discussed for arbitrary working points of the qubit. A method is developed that allows an exact formula for the phase…

Superconductivity · Physics 2009-11-11 J. Bergli , Y. M. Galperin , B. L. Altshuler

Quantum information processing exploits non-local functionality that has led to significant breakthroughs in the successful deployment of quantum mechanical protocols. In this regard, we address the dynamics of entanglement and coherence…

We propose a level-resolved protocol in a hybrid architecture for connecting a superconducting qubit and a magnon mode contained within a microwave cavity (resonator) to generate the local and global entangled states, enabling a wide range…

Quantum Physics · Physics 2022-03-01 Shi-fan Qi , Jun Jing

In an ensemble of two-level atoms that can be described in terms of a collective spin, entangled states can be used to enhance the sensitivity of interferometric precision measurements. While non-Gaussian spin states can produce larger…

Quantum Gases · Physics 2021-12-06 Youcef Baamara , Alice Sinatra , Manuel Gessner