
Alex Jenkins
Staff researcher
Spintronics
Alex finished both his undergraduate (MPhys) and postdoctoral (PhD) studies at the University of Leeds, which focused on the unconventional proximity effect in superconductor/ferromagnet hetereostructures. He then moved to Spintec labs in Grenoble where he performed the high frequency characterization of a range of magnetic systems, including in-plane and out-of-plane magnetic layers and coupled synthetic antiferromagnetic layers for both GMR spin valves and MgO based magnetic tunnel junctions. In order to fully understand the dynamical behavior of these systems, measurements in both the frequency and time domain were performed at both room temperature and low temperatures.
Alex then moved to CNRS/Thales in Palaiseau, France, where he focused on the use of vortex oscillators as a potential high frequency detector. They showed that when excited by an rf frequency current, the vortex will be excited to very large orbit radii, which can be used to switch the chirality and polarity of the vortex, and even to remove the vortex completely from the free layer, an effect shown to be the basis of a highly efficient threshold detector.
Alex started as a staff researcher at INL in March 2016, focusing on the high frequency characterization of magnetic tunnel junction based spin torque oscillators. He is in charge of the high frequency measurement lab, and is focused on the development of magnetic vortex-based oscillators for a range of applications, including frequency generators, detectors, energy harvesting and neuromorphic computing architectures.
Selected Publications
- AS Jenkins, LSE Alvarez, PP Freitas, R Ferreira
Digital and analogue modulation and demodulation scheme using vortex-based spin torque nano-oscillators
Scientific reports 10 (1), 1-7, 2020
- AS Jenkins, LSE Alvarez, R Dutra, RL Sommer, PP Freitas, R Ferreira
Wideband high-resolution frequency-to-resistance converter based on nonhomogeneous magnetic-state transitions
Physical Review Applied 13 (1), 014046, 2020
- AS Jenkins, LSE Alvarez, PP Freitas, R Ferreira
Nanoscale true random bit generator based on magnetic state transitions in magnetic tunnel junctions
Scientific reports 9 (1), 1-6, 2019
- M Tarequzzaman, AS Jenkins, T Böhnert, J Borme, L Martins, E Paz,…
Broadband voltage rectifier induced by linear bias dependence in CoFeB/MgO magnetic tunnel junctions
Applied Physics Letters 112 (25), 252401, 2018
- AS Jenkins, R Lebrun, E Grimaldi, S Tsunegi, P Bortolotti, H Kubota, …
Spin-torque resonant expulsion of the vortex core for an efficient radiofrequency detection scheme
Nature nanotechnology 11 (4), 360-364, 2016