Simulating decoherence of two coupled spins using the generalized cluster correlation expansion

• URL: http://arxiv.org/abs/2402.18722v2
• Date: Sun, 21 Sep 2025 19:41:39 GMT
• Title: Simulating decoherence of two coupled spins using the generalized cluster correlation expansion
• Authors: Xiao Chen, Silas Hoffman, James N. Fry, Hai-Ping Cheng,
• Abstract summary: We simulate the coherence of two coupled electron spins interacting with a bath of nuclei using the generalized cluster correlation expansion (gCCE) method.<n>We study the dephasing of the coherent two-electron system by characterizing the $T$ and $T*$ of the two-electron reduced density matrix.
• Score: 2.269493042512289
• License: http://creativecommons.org/licenses/by-nc-sa/4.0/
• Abstract: We simulate the coherence of two coupled electron spins interacting with a bath of nuclei using the generalized cluster correlation expansion (gCCE) method. An exchange interaction between the electrons facilitates a family of entangling gates that can be spoiled by nuclear-induced dephasing. Consequently, we study the dephasing of the coherent two-electron system by characterizing the $T_2$ and $T_2^*$ of the two-electron reduced density matrix for various system parameters in the range mimicking magnetic molecules, including magnetic field strength and orientation, exchange interaction strength, distance between the two spins, minimum distance between electron and nuclei and between nuclei, and nuclei density. We find the optimal regime for each parameter in which the coherence time is maximized and provide a physical understanding of it.

Related papers

• Exploring the mechanisms of transverse relaxation of copper(II)-phthalocyanine spin qubits [9.695800379962364]
  Molecular spin qubits are promising candidates for quantum technologies, but their performance is limited by decoherence arising from diverse mechanisms.<n>Here we present a systematic experimental and theoretical framework for analyzing the mechanisms of transverse relaxation in copper(II) phthalocyanine (CuPc) diluted into diamagnetic phthalocyanine hosts.<n>Our work identifies favorable values of the electron spin density for quantum applications, and provides a transferable methodology for predicting ensemble coherence times.
  arXiv  Detail & Related papers  (2025-11-05T05:32:56Z)
• Molecular spin qudits to test generalized Bell inequalities [0.0]
  We show that Yb(trensal) molecular nanomagnet, embedding an electronic spin qubit coupled to a nuclear spin qudit, provides an ideal platform to probe entanglement in a qubit-qudit system.
  arXiv  Detail & Related papers  (2025-07-30T15:32:59Z)
• Harnessing Chiral Spin States in Molecular Nanomagnets for Quantum Technologies [44.1973928137492]
  We show that chiral qubits naturally suppress always-on interactions that can not be switched off in weakly coupled qubits. Our findings establish spin chirality engineering as a promising strategy for mitigating always-on interaction in entangling two chiral qubits in molecular quantum technologies.
  arXiv  Detail & Related papers  (2025-01-21T08:23:12Z)
• Interacting Circular Rydberg Atoms Trapped in Optical Tweezers [0.0]
  Circular Rydberg atoms (CRAs) ideally combine long coherence times and strong interactions. We report the measurement and characterization of the resonant dipole-dipole interaction between two CRAs.
  arXiv  Detail & Related papers  (2024-07-04T18:24:53Z)
• Entanglement Generation and Decoherence in a Two-Qubit System Mediated by Relativistic Quantum Field [0.0]
  We study a toy model of a quantum entanglement generation between two spins (qubits) mediated by a relativistic free scalar field. Because of the associated particle creation into an open system, the quantum state of spins is partially decohered. We calculate various quantities such as spin correlations, entanglement entropies, mutual information and negativity, and study their behaviors in various limiting situations.
  arXiv  Detail & Related papers  (2022-11-17T10:05:02Z)
• Wigner-molecularization-enabled dynamic nuclear field programming [2.545763876632975]
  We show efficient control of spin transfer between an artificial three-electron WM and the nuclear environment in a GaAs double QD. We confirm the multiplet spin structure of a WM, paving the way for active control of newly emerging correlated electron states for application in mesoscopic environment engineering.
  arXiv  Detail & Related papers  (2022-07-24T04:14:16Z)
• Probing dynamics of a two-dimensional dipolar spin ensemble using single qubit sensor [62.997667081978825]
  We experimentally investigate individual spin dynamics in a two-dimensional ensemble of electron spins on the surface of a diamond crystal. We show that this anomalously slow relaxation rate is due to the presence of strong dynamical disorder. Our work paves the way towards microscopic study and control of quantum thermalization in strongly interacting disordered spin ensembles.
  arXiv  Detail & Related papers  (2022-07-21T18:00:17Z)
• Quantum chaos and thermalization in the two-mode Dicke model [77.34726150561087]
  We discuss the onset of quantum chaos and thermalization in the two-mode Dicke model. The two-mode Dicke model exhibits normal to superradiant quantum phase transition. We show that the temporal fluctuations of the expectation value of the collective spin observable around its average are small and decrease with the effective system size.
  arXiv  Detail & Related papers  (2022-07-08T11:16:29Z)
• Molecular formations and spectra due to electron correlations in three-electron hybrid double-well qubits [0.0]
  Wigner molecules (WMs) form in three-electron hybrid qubits based on GaAs asymmetric double quantum dots. FCI calculations enable prediction of the energy spectra and the intrinsic spatial and spin structures of the many-body wave functions. FCI methodology can be straightforwardly extended to treat valleytronic two-band Si/SiGe hybrid qubits.
  arXiv  Detail & Related papers  (2022-04-05T14:28:14Z)
• Phase diagram and post-quench dynamics in a double spin-chain system in transverse fields [4.179207589922213]
  We study the physics of a toy multiferroic model by coupling two distinct dipolar XXZ models in transverse fields. We find that the spin-spin interactions lead to a sizeable quadratic shift in the oscillation frequency as the inter-chain coupling is increased. This suggests a limited control mechanism for faster information transfer in magnetic spin chains using electric fields that harnesses the electric dipoles as intermediaries.
  arXiv  Detail & Related papers  (2021-11-15T15:18:01Z)
• Relativistic aspects of orbital and magnetic anisotropies in the chemical bonding and structure of lanthanide molecules [60.17174832243075]
  We study the electronic and ro-vibrational states of heavy homonuclear lanthanide Er2 and Tm2 molecules by applying state-of-the-art relativistic methods. We were able to obtain reliable spin-orbit and correlation-induced splittings between the 91 Er2 and 36 Tm2 electronic potentials dissociating to two ground-state atoms.
  arXiv  Detail & Related papers  (2021-07-06T15:34:00Z)
• Anisotropic electron-nuclear interactions in a rotating quantum spin bath [55.41644538483948]
  Spin-bath interactions are strongly anisotropic, and rapid physical rotation has long been used in solid-state nuclear magnetic resonance. We show that the interaction between electron spins of nitrogen-vacancy centers and a bath of $13$C nuclear spins introduces decoherence into the system. Our findings offer new insights into the use of physical rotation for quantum control with implications for quantum systems having motional and rotational degrees of freedom that are not fixed.
  arXiv  Detail & Related papers  (2021-05-16T06:15:00Z)
• Molecular Interactions Induced by a Static Electric Field in Quantum Mechanics and Quantum Electrodynamics [68.98428372162448]
  We study the interaction between two neutral atoms or molecules subject to a uniform static electric field. Our focus is to understand the interplay between leading contributions to field-induced electrostatics/polarization and dispersion interactions.
  arXiv  Detail & Related papers  (2021-03-30T14:45:30Z)
• Controlled coherent dynamics of [VO(TPP)], a prototype molecular nuclear qudit with an electronic ancilla [50.002949299918136]
  We show that [VO(TPP)] (vanadyl tetraphenylporphyrinate) is a promising system suitable to implement quantum computation algorithms. It embeds an electronic spin 1/2 coupled through hyperfine interaction to a nuclear spin 7/2, both characterized by remarkable coherence.
  arXiv  Detail & Related papers  (2021-03-15T21:38:41Z)
• Chemical tuning of spin clock transitions in molecular monomers based on nuclear spin-free Ni(II) [52.259804540075514]
  We report the existence of a sizeable quantum tunnelling splitting between the two lowest electronic spin levels of mononuclear Ni complexes. The level anti-crossing, or magnetic clock transition, associated with this gap has been directly monitored by heat capacity experiments. The comparison of these results with those obtained for a Co derivative, for which tunnelling is forbidden by symmetry, shows that the clock transition leads to an effective suppression of intermolecular spin-spin interactions.
  arXiv  Detail & Related papers  (2021-03-04T13:31:40Z)
• Probing the coherence of solid-state qubits at avoided crossings [51.805457601192614]
  We study the quantum dynamics of paramagnetic defects interacting with a nuclear spin bath at avoided crossings. The proposed theoretical approach paves the way to designing the coherence properties of spin qubits from first principles.
  arXiv  Detail & Related papers  (2020-10-21T15:37:59Z)
• Electrically tuned hyperfine spectrum in neutral Tb(II)(Cp$^{\ m{iPr5}}$)$_2$ single-molecule magnet [64.10537606150362]
  Both molecular electronic and nuclear spin levels can be used as qubits. In solid state systems with dopants, an electric field was shown to effectively change the spacing between the nuclear spin qubit levels. This hyperfine Stark effect may be useful for applications of molecular nuclear spins for quantum computing.
  arXiv  Detail & Related papers  (2020-07-31T01:48:57Z)
• Cluster-correlation expansion for studying decoherence of clock transitions in spin baths [0.46408356903366527]
  Clock transitions (CTs) of central spins have long coherence times because their frequency fluctuations vanish in the linear order of external field noise. Various quantum many-body methods have been developed to study the decoherence of a central spin in spin baths. We develop a modified CCE method to tackle this class of decoherence problems.
  arXiv  Detail & Related papers  (2020-07-01T12:11:55Z)
• Optically pumped spin polarization as a probe of many-body thermalization [50.591267188664666]
  We study the spin diffusion dynamics of 13C in diamond, which we dynamically polarize at room temperature via optical spin pumping of engineered color centers. We find good thermal contact throughout the nuclear spin bath, virtually independent of the hyperfine coupling strength. Our results open intriguing opportunities to study the onset of thermalization in a system by controlling the internal interactions within the bath.
  arXiv  Detail & Related papers  (2020-05-01T23:16:33Z)

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.