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Motivated by the growing interest in accessing the spin structure of multi-boson processes and in measuring quantum entanglement at high energies, we study polarisation and spin-correlation coefficients in di-boson systems. We show that…

High Energy Physics - Phenomenology · Physics 2025-01-13 Michele Grossi , Giovanni Pelliccioli , Alessandro Vicini

The efficiency of a quantum metrology protocol can be significantly diminished by the interaction of the system with its environment, leading to a loss of purity and, as a result, a mixed state for the probing system. An example is the…

Quantum Physics · Physics 2025-02-28 Eduardo Serrano-Ensástiga , Chryssomalis Chryssomalakos , John Martin

We provide the first evidence for coherence and Rabi oscillations of spin-solitons pinned by the local breaking of translational symmetry in isotropic Heisenberg chains (simple antiferromagnetic-N\'{e}el or spin-Peierls).We show that these…

Strongly Correlated Electrons · Physics 2015-06-18 Sylvain Bertaina , Charles-Emmanuel Dutoit , Johan Van Tol , Martin Dressel , Bernard Barbara , Anatoli Stepanov

The precision of a quantum sensor can overcome its classical counterpart when its constituents are entangled. In gaussian squeezed states, quantum correlations lead to a reduction of the quantum projection noise below the shot noise limit.…

Using concepts of geometric orthogonality and linear independence, we logically deduce the form of the Pauli spin matrices and the relationships between the three spatially orthogonal basis sets of the spin-1/2 system. Rather than a…

Quantum Physics · Physics 2016-06-13 Dallin S. Durfee , James L. Archibald

Quantum coherence quantifies the amount of superposition in a quantum system, and is the reason and resource behind several phenomena and technologies. It depends on the natural basis in which the quantum state of the system is expressed,…

Quantum Physics · Physics 2021-08-13 Ingita Banerjee , Kornikar Sen , Chirag Srivastava , Ujjwal Sen

We consider an electron confined in a gated nanowire quantum dot (NQD) with arbitrarily strong spin-orbit coupling (SOC) and weak static magnetic field, and treat the latter as a perturbation to seek the maximal spin-motion entangled states…

Mesoscale and Nanoscale Physics · Physics 2024-04-23 Kuo Hai , Xuefang Deng , Qiong Chen , Wenhua Hai

It has become common practice to model large spin ensembles as an effective pseudospin with total angular momentum J = N x j, where j is the spin per particle. Such approaches (at least implicitly) restrict the quantum state of the ensemble…

Quantum Physics · Physics 2012-01-24 Ben Q. Baragiola , Bradley A. Chase , JM Geremia

A promising venue for hybrid quantum computation involves the strong coupling between impurity spins and superconducting resonators. One strategy to control and enhance this coupling is to prepare the resonator in a non-classical state,…

Quantum Physics · Physics 2022-03-14 Inbar Shani , Emanuele G. Dalla Torre , Michael Stern

We propose a measurement-based quantum metrology protocol in a composite model, where the probe system (a spin ensemble) is coupled to an ancillary two-level system (qubit) with a general Heisenberg XXZ interaction. With an optimized and…

Quantum Physics · Physics 2026-01-23 Peng Chen , Jun Jing

Many protocols require precise rotation measurement. Here we present a general class of states that surpass the shot noise limit for measuring rotation around arbitrary axes. We then derive a quantum Cram\'er-Rao bound for simultaneously…

Quantum Physics · Physics 2019-03-20 Aaron Z. Goldberg , Daniel F. V. James

Lying at the heart of quantum mechanics, coherence has recently been studied as a key resource in quantum information theory. Quantum steering, a fundamental notion originally considered by Schr{\"o}dinger, has also recently received much…

Quantum Physics · Physics 2016-01-25 Xueyuan Hu , Antony Milne , Boyang Zhang , Heng Fan

A pair of quantum observables diagonal in the same "incoherent" basis can be measured jointly, so some coherence is obviously required for measurement incompatibility. Here we first observe that coherence in a single observable is linked to…

Quantum Physics · Physics 2022-01-11 Jukka Kiukas , Daniel McNulty , Juha-Pekka Pellonpää

In the scenario of the probe-ancilla interaction, we propose a quantum metrology protocol by the unconditional measurement on the ancillary qubit after an optimized period of joint evolution from product state. Its key element is the…

Quantum Physics · Physics 2025-09-12 Peng Chen , Jun Jing

The ability to determine precisely the separation of two frequencies is fundamental to spectroscopy, yet the resolution limit poses a critical challenge: distinguishing two incoherent signals becomes impossible when their frequencies are…

Quantum Physics · Physics 2025-12-29 Qingyun Cao , Genko T. Genov , Yaoming Chu , Jianming Cai , Yu Liu , Alex Retzker , Fedor Jelezko

Non-commutative spacetime and quantum groups have been argued to capture non-classical features of spacetime and its symmetries in the low-energy limit of quantum gravity. In this letter, we show that employing the $SU_q(2)$ quantum group…

Quantum Physics · Physics 2026-05-29 Vittorio D'Esposito , Giuseppe Fabiano , Domenico Frattulillo

Treating the infinite-dimensional Hilbert space of non-abelian gauge theories is an outstanding challenge for classical and quantum simulations. Here, we introduce $q$-deformed Kogut-Susskind lattice gauge theories, obtained by deforming…

Quantum Physics · Physics 2023-11-27 Torsten V. Zache , Daniel González-Cuadra , Peter Zoller

The quantum geometric tensor (QGT) embodies the geometry of the eigenstates of a system's Hamiltonian, and its full characterization across diverse quantum systems is essential. However, it is challenging to characterize the QGT of…

Mesoscale and Nanoscale Physics · Physics 2026-02-26 Shu-Hui Zhang , Jin Yang , Ding-Fu Shao , Jia-Ji Zhu , Wen-Long You , Wen Yang , Kai Chang

It is shown that the quantum Hamiltonian characterising a non-relativistic electron under the influence of an external spherical symmetric electromagnetic potential exhibits a supersymmetric structure. Both cases, spherical symmetric scalar…

Mathematical Physics · Physics 2025-05-21 Georg Junker

General dynamic properties like controllability and simulability of spin systems, fermionic and bosonic systems are investigated in terms of symmetry. Symmetries may be due to the interaction topology or due to the structure and…

Quantum Physics · Physics 2011-11-28 Robert Zeier , T. Schulte-Herbrueggen