Quantum coherent spin–electric control in a molecular nanomagnet at clock transitions
Nature Physics Springer Science and Business Media LLC 17:11 (2021) 1205-1209
Coherent electric field manipulation of Fe3+-spins in PbTiO3
Science Advances American Association for the Advancement of Science 7:10 (2021) eabf8103
Abstract:
Magnetoelectrics, materials which exhibit coupling between magnetic and electric degrees of freedom, not only offer a rich environment for studying the fundamental materials physics of spin-charge coupling, but also present opportunities for future information technology paradigms. We present results of electric field manipulation of spins in a ferroelectric medium using dilute Fe3+-doped PbTiO3 as a model system. Combining first-principles calculations and electron paramagnetic resonance (EPR), we show that the Fe3+ spins are preferentially aligned perpendicular to the ferroelectric polar axis, which we can manipulate using an electric field. We also demonstrate coherent control of the phase of spin superpositions by applying electric field pulses during time-resolved EPR measurements. Our results suggest a new pathway towards the manipulation of spins for quantum and classical spintronics.Electric field control of spins in molecular magnets
Physical Review Letters American Physical Society 122:3 (2019) 037202
Abstract:
Coherent control of individual molecular spins in nanodevices is a pivotal prerequisite for fulfilling the potential promised by molecular spintronics. By applying electric field pulses during time-resolved electron spin resonance measurements, we measure the sensitivity of the spin in several antiferromagnetic molecular nanomagnets to external electric fields. We find a linear electric field dependence of the spin states in Cr7Mn, an antiferromagnetic ring with a ground-state spin of S ¼ 1, and in a frustrated Cu3 triangle, both with coefficients of about 2 rad s−1=V m−1. Conversely, the antiferromagnetic ring Cr7Ni, isomorphic with Cr7Mn but with S ¼ 1=2, does not exhibit a detectable effect. We propose that the spinelectric field coupling may be used for selectively controlling individual molecules embedded in nanodevices.Strong coupling of microwave photons to antiferromagnetic fluctuations in an organic magnet
Physical Review Letters American Physical Society 119:14 (2017) 147701
Abstract:
Coupling between a crystal of di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH) radicals and a superconducting microwave resonator is investigated in a circuit quantum electrodynamics (cQED) architecture. The crystal exhibits paramagnetic behavior above 4 K, with antiferromagnetic correlations appearing below this temperature, and we demonstrate strong coupling at base temperature. The magnetic resonance acquires a field angle dependence as the crystal is cooled down, indicating anisotropy of the exchange interactions. These results show that multi-spin modes in organic crystals are suitable for cQED, offering a platform for their coherent manipulation. They also utilize the cQED architecture as a way to probe spin correlations at low temperature.Fault-tolerant qubit encoding using a spin-7/2 qudit
Physical Review A American Physical Society 108 (2023) 062403