Two-spin and multi-spin quantum entanglement in V12 polyoxovanadate molecular nanomagnet

Decoherence of intermolecular entanglement in exchange-coupled nanomagnets

We theoretically investigate the hyperfine-induced decoherence in a pair of spin-cluster qubits, consisting of two exchange-coupled heterometallic wheels. We identify two distinct regimes in the decoherence of intermolecular entanglement and show that this can be substantially recovered through dynamical decoupling. Different chemical elements and physical processes are responsible for the decoherence of the singlet-triplet superposition, resulting in a wider tunability of its decoherence time.

Towards the chemical tuning of entanglement in molecular nanomagnets

Antiferromagnetic spin rings represent prototypical realizations of highly correlated, low-dimensional systems. Here we theoretically show how the introduction of magnetic defects by controlled chemical substitutions results in a strong spatial modulation of spin-pair entanglement within each ring. Entanglement between local degrees of freedom (individual spins) and collective ones (total ring spins) are shown to coexist in exchange-coupled ring dimers, as can be deduced from general symmetry arguments. We verify the persistence of these features at finite temperatures, and discuss them in ter…

腔体中局部域壁的宏观纠缠

Macroscopic entanglement between localized domain walls inside a cavity

该研究在光学腔中通过调控钉扎势能和驱动频率，实现纳米磁条中两个局部域壁的稳定可调宏观纠缠。

Unravelling the Spin Dynamics of Molecular Nanomagnets with Four-Dimensional Inelastic Neutron Scattering

Molecular Nanomagnets have attracted the attention of the scientific community since the rich physics behind their magnetic behaviour make them ideal test-beds for fundamental concepts in quantum mechanics. Sophisticated experiments and targeted research activities have also unveiled their potential for several technological applications. Inelastic neutron scattering is a powerful and widely used technique to investigate the properties of these systems. The new generation of spectrometers, equipped with arrays of position-sensitive detectors, enable to efficiently measure the neutron cross-sec…

Detection of entanglement between collective spins

Entanglement between individual spins can be detected by using thermodynamics quantities as entanglement witnesses. This applies to collective spins also, provided that their internal degrees of freedom are frozen, as in the limit of weakly-coupled nanomagnets. Here, we extend such approach to the detection of entanglement between subsystems of a spin cluster, beyond such weak-coupling limit. The resulting inequalities are violated in spin clusters with different geometries, thus allowing the detection of zero- and finite-temperature entanglement. Under relevant and experimentally verifiable c…

用于检验广义贝尔不等式的分子自旋量子多体（qudit）

Molecular spin qudits to test generalized Bell inequalities

本研究利用Yb(trensal)分子纳米磁体构建qubit-qudit系统，通过优化脉冲序列和含退相干的数值模拟验证其可违反广义贝尔不等式，证明纠缠鲁棒性，并提出分子自旋三聚体的qudit-qudit纠缠研究方案。