Single magnetic molecules may be the smallest functional magnets. An electric-field controllable spin state of magnetic molecules is of fundamental importance for applications while its realization remains challenging. To date the observed spin-electric interaction based on spin-orbit coupling or spin dipole coupling is useful to tune fine spin structures but too weak to flip the spin state. In this work, we propose a new mechanism to realize enhanced spin-electric coupling and flip the spin states by tuning the spin superexchange between local spins. Using first-principles calculations and Heisenberg Hamiltonian, we demonstrate this effect in a family of magnetic molecules, transition metallic Porphyrins. We show that their d-π and π-π spin superexchange couplings are determined by the relative energies of d and π electronic states, which are sensitive to the applied electric field. Therefore, applying electric field can tune a wide range of magnetic ground states, including ferromagnetic, ferrimagnetic, and antiferromagnetic configurations. This spin-electric coupling may provide a new approach for designing and controlling molecular spintronics.
Electrically tunable orbital coupling and quantum light emission from O-band quantum dot molecules
Walter Schottky Institute, TUM School of Natural Sciences, Technical University of Munich（慕尼黑工业大学沃尔特·施特克特研究所）；Munich Center for Quantum Science and Technology (MCQST)（慕尼黑量子科学与技术中心）；Center for Quantum Engineering (ZQE) and School of Computation, Information and Technology, Technical University of Munich（慕尼黑工业大学量子工程中心与计算、信息与技术学院）；Julius-Maximilians-Universität Würzburg, Physikalisches Institut, Lehrstuhl für Technische Physik（维尔茨堡大学物理系技术物理教席）；Walter Schottky Institute, Technical University of Munich（慕尼黑工业大学沃尔特·施特克特研究所）；Saqura Technologies GmbH（萨库拉技术有限公司）；Karlsruhe Institute of Technology, Institute of Photonics and Quantum Electronics IQST（卡尔斯鲁厄理工学院光子学与量子电子学研究所）
Spin qubits with electrically gated polyoxometalate molecules
自旋量子比特为实现量子计算机提供了最有前途的途径之一。半导体量子点的最新结果表明，电控门控方案特别适合于实现一组通用的量子逻辑门。然而，对于这种半导体量子点来说，可扩展到更大数量的量子位仍然是一个问题。相比之下，化学自下而上的方法允许人们产生相同的单位，其中局域自旋代表量子位。分子磁性已经产生了广泛的系统与定制的性能，但分子允许电门控一直缺乏。在这里，我们建议使用聚氧乙烯酸盐[PMo 1/2 O 40（VO）2]q-，其中两个本地化的自旋-1/2可以通过中央核心的电子耦合。通过分子氧化还原电位的电操纵，可以改变核的电荷。通过这种设置，可以实现两个量子位门和量子位读出。
Electric Field Enhanced Hydrogen Storage on BN Sheet
使用密度泛函理论，我们表明，施加的电场通过极化氢分子以及基板，大大提高了BN片的储氢性能。在0.05 a. u.的电场存在下单个H2分子的吸附能。是0.48 eV，而在其不存在时为0.07 eV。当吸附一层H2分子时，每个H2分子的结合能从无场情况下的0.03 eV增加到存在0.045 a. u的电场时的0.14 eV/H2。7.5wt%的相应重量密度与DOE为2010年设定的6wt%系统目标一致。一旦去除所施加的电场，存储的H2分子可以容易地释放，从而使存储可逆。
