海森堡极限确定性超冷离子源

Nonlinear Phonon Interferometry at the Heisenberg Limit

Interferometers operating at or close to quantum limits of precision have found wide application in tabletop searches for physics beyond the standard model, the study of fundamental forces and symmetries of nature and foundational tests of quantum mechanics. The limits imposed by quantum fluctuations and measurement backaction on conventional interferometers ($δϕ\sim 1/\sqrt{N}$) have spurred the development of schemes to circumvent these limits through quantum interference, multiparticle interactions and entanglement. A prominent example of such schemes, the so-called $SU(1,1)$ interferometer…

Realization of a Bosonic Antiferromagnet

Quantum antiferromagnets are of broad interest in condensed matter physics as they provide a platform for studying exotic many-body states including spin liquids and high-temperature superconductors. Here, we report on the creation of a one-dimensional Heisenberg antiferromagnet with ultracold bosons. In a two-component Bose-Hubbard system, we switch the sign of the spin-exchange interaction and realize the isotropic antiferromagnetic Heisenberg model in an extended 70-site chain. Starting from a low-entropy Néel-ordered state, we use optimized adiabatic passage to approach the bosonic antifer…

利用自旋Bogoliubov哈密顿量实现海森堡极限自旋压缩

Heisenberg-limit spin squeezing with spin Bogoliubov Hamiltonian

本文证明单轴扭转哈密顿量基态的自旋压缩可达海森堡极限J^{-1}，并通过构造自旋Bogoliubov哈密顿量进行精确对角化，为在多种实验平台实现极限自旋压缩提供理论依据。

Optimal joint measurements of complementary observables by a single trapped ion

The uncertainty relations, pioneered by Werner Heisenberg nearly 90 years ago, set a fundamental limitation on the joint measurability of complementary observables. This limitation has long been a subject of debate, which has been reignited recently due to new proposed forms of measurement uncertainty relations. The present work is associated with a new error trade-off relation for compatible observables approximating two incompatible observables, in keeping with the spirit of Heisenberg's original ideas of 1927. We report the first \textsl{direct} test and confirmation of the tight bounds pre…

Interacting atomic interferometry for rotation sensing approaching the Heisenberg Limit

Atom interferometers provide exquisite measurements of the properties of non-inertial frames. While atomic interactions are typically detrimental to good sensing, efforts to harness entanglement to improve sensitivity remain tantalizing. Here we explore the role of interactions in an analogy between atomic gyroscopes and SQUIDs, motivated by recent experiments realizing ring shaped traps for ultracold atoms. We explore the one-dimensional limit of these ring systems with a moving weak barrier, such as that provided by a blue-detuned laser beam. In this limit, we employ Luttinger liquid theory …

通过囚禁离子阵列的绝热马赫-曾德尔干涉仪

Adiabatic Mach-Zehnder interferometer via an array of trapped ions

我们探讨了在横向场中通过一系列服从量子伊辛模型的囚禁离子实现海森堡限制马赫-曾德尔干涉的可能性。基于增加Ising相互作用，然后减小横场的绝热过程，我们证明了从顺磁性到铁磁性的完美转变，它可以用作多离子Mach-Zehnder干涉术的分束器。实现的NOON状态的离子，使海森堡限制干涉。使用目前可用的技术，超冷离子，我们讨论了我们的计划与全球业务的实验可行性。

基于囚禁离子量子计算机的泵浦方法计算动态结构因子

Dynamical structure factor with a pumping approach on a trapped-ion quantum computer

研究在囚禁离子量子计算机上计算动态结构因子的可行性，引入泵浦方法计算DSF $S(q,\omega)$，能针对特定频率值，利用含时哈密顿量演化初始态，相比之前方法，针对少数频率值时可显著减少测量开销。

在神经网络波函数中利用循环结构进行方格上Heisenberg反铁磁体的大规模模拟

Leveraging recurrence in neural network wavefunctions for large-scale simulations of Heisenberg antiferromagnets on the square lattice

本研究采用循环神经网络（RNNs）作为变分拟设，通过迭代再训练的迁移学习技术，高效模拟了超过1000个自旋的方格Heisenberg反铁磁体基态，并准确提取了热力学极限下的基态性质。