Nonclassicality Analysis and Entanglement Witnessing in Spin-$1/2$ NMR Systems

• URL: http://arxiv.org/abs/2512.01100v1
• Date: Sun, 30 Nov 2025 21:54:34 GMT
• Title: Nonclassicality Analysis and Entanglement Witnessing in Spin-$1/2$ NMR Systems
• Authors: Fatemeh Khashami,
• Abstract summary: We investigate quantum features and non-classical nature of two-spin-$1/2$ NMR systems at thermal equilibrium under external magnetic fields.<n>We derive closed-form analytical expressions for the quantum elements and show how they depend on temperature and magnetic field strength.<n>We demonstrate that at zero temperature, the system exhibits a quantum critical point, characterized by non-analytic behavior in the measures of coherence, and a sharp peak in mixedness.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We investigate quantum features and non-classical nature of two-spin-$1/2$ NMR systems at thermal equilibrium under external magnetic fields. More specifically, using suitable quantifiers, we analyze quantum coherence, mixedness, and entanglement in NMR systems and examine their features within the system. We derive closed-form analytical expressions for the quantum elements and show how they depend on temperature and magnetic field strength. We demonstrate that at zero temperature, the system exhibits a quantum critical point, characterized by non-analytic behavior in the measures of coherence, and a sharp peak in mixedness. Moreover, we analyze the entanglement of the system using a suitable entanglement witness. This provides an experimentally friendly setting for testing entanglement in NMR systems. In other words, the witness links the entanglement in the system to quantum observables, making it directly provable in NMR experiments. We establish a connection between quantum information quantifiers and experimentally accessible NMR spectra of the system, enabling the quantification of entanglement, coherence, and mixedness through NMR signal processing.

Related papers

• Quantum Entanglement Control in Two-Spin-1/2 NMR Systems Through Magnetic Fields and Temperature [0.0]
  We show how entanglement depends on temperature and magnetic field strength, resulting in a threshold temperature beyond which entanglement vanishes.<n>At zero temperature, the system exhibits a quantum critical point, characterized by non-analytic behavior in the measure of entanglement.<n>These findings provide insights into the thermal control of quantum features, with implications for quantum-enhanced NMR, low-temperature spectroscopy, and emerging quantum technologies.
  arXiv  Detail & Related papers  (2025-11-30T20:04:42Z)
• Probing nonlocal correlations in magnetic rare-earth clusters [0.0]
  We study rare-earth spin complexes and their unique magnetic properties.<n>Our analysis reveals a one-to-one correspondence between structures in the differential conductance profiles.<n>Distinct braiding patterns in the conductance profiles are shown to correspond to stepwise changes in the entanglement entropy.
  arXiv  Detail & Related papers  (2024-12-01T03:43:30Z)
• Quantum Information Resources in Spin-1 Heisenberg Dimer Systems [0.0]
  We explore the quantum information resources within bipartite pure and mixed states of the quantum spin-1 Heisenberg dimer system.<n>We derive the system's density operator at thermal equilibrium and establish a mathematical framework for analyzing quantum resource metrics.
  arXiv  Detail & Related papers  (2024-09-12T14:36:21Z)
• Fourier Neural Operators for Learning Dynamics in Quantum Spin Systems [77.88054335119074]
  We use FNOs to model the evolution of random quantum spin systems. We apply FNOs to a compact set of Hamiltonian observables instead of the entire $2n$ quantum wavefunction.
  arXiv  Detail & Related papers  (2024-09-05T07:18:09Z)
• Geometric quantum discord and coherence in a dipolar interacting magnetic system [0.0]
  This work explores the effect of the quantum-level crossing, induced by the magnetic anisotropies of dipolar interacting systems, on the quantum discord and coherence of the system. The results show that, while the quantum discord has a clear signature of the quantum level-crossing, the basis dependence of the quantum coherence hides the crossover regarding the measured basis.
  arXiv  Detail & Related papers  (2023-01-07T16:45:17Z)
• Full counting statistics as probe of measurement-induced transitions in the quantum Ising chain [62.997667081978825]
  We show that local projective measurements induce a modification of the out-of-equilibrium probability distribution function of the local magnetization. In particular we describe how the probability distribution of the former shows different behaviour in the area-law and volume-law regimes.
  arXiv  Detail & Related papers  (2022-12-19T12:34:37Z)
• Sensing of magnetic field effects in radical-pair reactions using a quantum sensor [50.591267188664666]
  Magnetic field effects (MFE) in certain chemical reactions have been well established in the last five decades. We employ elaborate and realistic models of radical-pairs, considering its coupling to the local spin environment and the sensor. For two model systems, we derive signals of MFE detectable even in the weak coupling regime between radical-pair and NV quantum sensor.
  arXiv  Detail & Related papers  (2022-09-28T12:56:15Z)
• Visualizing spinon Fermi surfaces with time-dependent spectroscopy [62.997667081978825]
  We propose applying time-dependent photo-emission spectroscopy, an established tool in solid state systems, in cold atom quantum simulators. We show in exact diagonalization simulations of the one-dimensional $t-J$ model that the spinons start to populate previously unoccupied states in an effective band structure. The dependence of the spectral function on the time after the pump pulse reveals collective interactions among spinons.
  arXiv  Detail & Related papers  (2021-05-27T18:00:02Z)
• Basis-independent system-environment coherence is necessary to detect magnetic field direction in an avian-inspired quantum magnetic sensor [77.34726150561087]
  We consider an avian-inspired quantum magnetic sensor composed of two radicals with a third "scavenger" radical under the influence of a collisional environment. We show that basis-independent coherence, in which the initial system-environment state is non-maximally mixed, is necessary for optimal performance.
  arXiv  Detail & Related papers  (2020-11-30T17:19:17Z)
• Spin Entanglement and Magnetic Competition via Long-range Interactions in Spinor Quantum Optical Lattices [62.997667081978825]
  We study the effects of cavity mediated long range magnetic interactions and optical lattices in ultracold matter. We find that global interactions modify the underlying magnetic character of the system while introducing competition scenarios. These allow new alternatives toward the design of robust mechanisms for quantum information purposes.
  arXiv  Detail & Related papers  (2020-11-16T08:03:44Z)
• Open Quantum Dynamics Theory of Spin Relaxation: Application to $\mu$SR and Low-Field NMR Spectroscopies [0.0]
  An open quantum system refers to a system that can describe time irreversible dynamics through which the system evolves toward the thermal equilibrium state. We present a quantum mechanically rigorous theory in order to help an analysis of spectra obtained from the advanced nuclear magnetic resonance (NMR) and muon spin rotation, relaxation or resonance techniques.
  arXiv  Detail & Related papers  (2020-04-15T10:44:07Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.