English
Related papers

Related papers: Optimal Control of Spin Squeezing in 2D Finite-Ran…

200 papers

Spin squeezed states are a class of entangled states of spins that have practical applications to precision measurements. In recent years spin squeezing with one-axis twisting (OAT) has been demonstrated experimentally with spinor BECs with…

Quantum Physics · Physics 2013-05-15 Chao Shen , Luming Duan

This article is aimed at extending the framework of optimal control techniques to the situation where the control field values are restricted to a finite set. We propose a generalization of the standard GRAPE algorithm suited to this…

Optimization and Control · Mathematics 2015-10-28 G. Dridi , M. Lapert , Julien Salomon , D Sugny , S. J. Glaser

Spin squeezing (SS) is a recognized resource for realizing measurement precision beyond the standard quantum limit $\propto 1/\sqrt{N}$. The rudimentary one-axis twisting (OAT) interaction can facilitate SS and has been realized in diverse…

Quantum Gases · Physics 2019-10-16 Feng Chen , Jun-Jie Chen , Ling-Na Wu , Yong-Chun Liu , Li You

Spins in solids and molecules are promising for applications of quantum sensing technology. The sensitivity of the quantum sensing depends on how precisely spin observables can be determined in the measurement, and is intrinsically limited…

Quantum Physics · Physics 2025-11-21 Yifan Song , Nabiha Hasan , Susumu Takahashi

Efficient control over entanglement in spin chains is useful for quantum information processing applications. In this paper, we propose the use of a combination of two different configurations of strong static and oscillating fields to…

Long-range spin-spin interactions are known to generate non-equilibrium dynamics which can squeeze the collective spin of a quantum spin ensemble in a scalable manner, leading to states whose metrologically useful entanglement grows with…

Quantum Physics · Physics 2024-04-22 Tommaso Roscilde , Filippo Caleca , Adriano Angelone , Fabio Mezzacapo

This study investigates spin squeezed states in nuclear magnetic resonance (NMR) quadrupolar systems with spins $I=3/2$ and $I=7/2$ at room temperature, taking into account the effects of relaxation on the dynamics. The origin of spin…

We study the non-equilibrium dynamics of a quantum spin 1/2 XXZ model confined in a two-dimensional bi-layer system, with couplings mediated by inverse power-law interactions, falling off with distance $r$ as $1/r^{\alpha}$, and…

Quantum Physics · Physics 2024-06-27 Arman Duha , Thomas Bilitewski

Entangled spin squeezed states generated via dipolar interactions in lattice models provide unique opportunities for quantum enhanced sensing and are now within reach of current experiments. A critical question in this context is which…

Quantum Physics · Physics 2024-02-27 David Wellnitz , Mikhail Mamaev , Thomas Bilitewski , Ana Maria Rey

Strongly interacting spins underlie many intriguing phenomena and applications ranging from magnetism to quantum information processing. Interacting spins combined with motion display exotic spin transport phenomena, such as superfluidity…

Spin-squeezed states constitute a valuable entanglement resource capable of surpassing the standard quantum limit (SQL). However, spin-squeezed states only enable sub-SQL uncertainty within a narrow parametric window near some specific…

Quantum Physics · Physics 2025-10-10 Jinye Wei , Jungeng Zhou , Yi Shen , Jiahao Huang , Chaohong Lee

Spin squeezing, as a crucial quantum resource, plays a pivotal role in quantum metrology, enabling us to achieve high-precision parameter estimation schemes. Here we investigate the spin squeezing and the quantum phase transition in an…

Quantum Physics · Physics 2023-11-29 Lei Shao , Libin Fu

Atom interferometers are reaching sensitivities fundamentally constrained by quantum fluctuations. A main challenge is to integrate entanglement into quantum sensing protocols to enhance precision while ensuring robustness against noise and…

Controlling the quantum many-body state of arrays of qudits, possessing a large local Hilbert space, opens the path to a broad range of possibilities for many-particle entanglement, interesting both for fundamental quantum science, as well…

Quantum Physics · Physics 2023-09-12 Youssef Trifa , Tommaso Roscilde

Balancing high sensitivity with a broad dynamic range is a fundamental challenge in measurement science, as improving one often compromises the other. While traditional quantum metrology has prioritized enhancing local sensitivity, a large…

Quantum Physics · Physics 2025-07-25 Qi Liu , Ming Xue , Matthew Radzihovsky , Xinwei Li , Denis V. Vasilyev , Ling-Na Wu , Vladan Vuletić

We investigate optimal control strategies for state to state transitions in a model of a quantum dot molecule containing two active strongly interacting electrons. The Schrodinger equation is solved nonperturbatively in conjunction with…

Quantum Physics · Physics 2016-08-14 R. Nepstad , L. Sælen , I. Degani , J. P. Hansen

It has been shown elsewhere that two spatially separated atoms can jointly absorb one photon, whose frequency is equal to the sum of the transition frequencies of the two atoms. We describe this process in the presence of an ensemble of…

Quantum Physics · Physics 2020-05-13 Vincenzo Macrí , Franco Nori , Salvatore Savasta , David Zueco

We investigate several control strategies for the transport of an excitation along a spin chain. We demonstrate that fast, high fidelity transport can be achieved using protocols designed with differentiable programming. Building on this,…

Quantum Physics · Physics 2022-11-30 Luuk Coopmans , Steve Campbell , Gabriele De Chiara , Anthony Kiely

We show how mapping techniques inherent to $N^{2}$-dimensional discrete phase spaces can be used to treat a wide family of spin systems which exhibits squeezing and entanglement effects. This algebraic framework is then applied to the…

Quantum Physics · Physics 2013-07-16 Marcelo A. Marchiolli , Diógenes Galetti , Tiago Debarba

A major obstacle in the way of practical quantum computing is achieving scalable and robust high-fidelity entangling gates. To this end, quantum control has become an essential tool, as it can make the entangling interaction resilient to…

Quantum Physics · Physics 2022-10-05 Christophe H. Valahu , Iason Apostolatos , Sebastian Weidt , Winfried K. Hensinger