A5021852018- Magnetic properties of thin films
- Advanced Optical Sensing Technologies
- Advanced Semiconductor Detectors and Materials
- Quantum and electron transport phenomena
- Magnetic Properties and Applications
- Quantum Information and Cryptography
- Physics of Superconductivity and Magnetism
- Photonic and Optical Devices
- Advanced Memory and Neural Computing
- Magneto-Optical Properties and Applications
- Magnetic and transport properties of perovskites and related materials
- ZnO doping and properties
- Magnetic Field Sensors Techniques
- Theoretical and Computational Physics
- Advanced Fiber Laser Technologies
University of Cambridge
2012-2014
Université Joseph Fourier
2013-2014
Université Grenoble Alpes
2014
Centre National de la Recherche Scientifique
2014
Spintronique et Technologie des Composants
2013-2014
CEA Grenoble
2014
Institut Nanosciences et Cryogénie
2014
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2014
Institut polytechnique de Grenoble
2014
University of Leeds
2007-2010
We have studied field- and current-driven domain-wall (DW) creep motion in a perpendicularly magnetized Co/Pt multilayer wire by real-time Kerr microscopy. The application of dc current density approximately < 10(7) A/cm2 assisted only the DW creeping under field same direction as electron flow, signature spin-transfer torque effects. develop model dealing with both bidirectional effects Joule heating, dynamical exponent mu=1/4 for creep, use it to quantify efficiency 3.6+/-0.6 Oe cm2/MA our...
Superconducting nanowire single photon detectors (SNSPDs) are a key enabling technology for optical quantum information science. In this paper we demonstrate SNSPD fabricated on lithium niobate, an important material high speed integrated photonic circuits. We report system detection efficiency of 0.15% at 1 kHz dark count rate with maximum ~1% close to the critical current 1550 nm wavelength parallel wire front side illumination. There is clear scope improving performance further materials...
The device physics of parallel-wire superconducting nanowire single photon detectors is based on a cascade process. Using nano-optical techniques and parallel wire with spatially separate pixels, we explicitly demonstrate the single- multi-photon triggering regimes. We develop model for describing efficiency detector operating in arm-trigger regime. investigate timing response when illuminating pixel two pixels. see change active area between regimes find two-pixel trigger regime to have...
The domain wall processes in Hall bar devices patterned from Co∕Pt multilayers with perpendicular magnetic anisotropy have been studied by Kerr microscopy and extraordinary effect measurements. samples are extremely thin (&lt;2nm) so that they show full remanence a square hysteresis loop coercive field of ∼25Oe. microscope observations the as-patterned bars shown an uncontrolled nucleation followed rapid propagation, without significant pinning. This shows exceeds any propagation pinning...
We have investigated the use of CoPt ultrathin multilayers as an alternative material for a high sensitivity Hall sensor, capable detecting very low fields at room temperature. present measurements Pt(25Å)/[Co(6Å)/Pt(12Å)]×2 (6 nm thick) sample with cross area 5×2.5 μm2 and coercive field 170 Oe, both continuous film patterned device. This sensor has SI = 3960 Ω/T is minimum change Bmin 2.6 nT/Hz1/2, better than similarly sized semiconductor sensors working
Field-current phase diagrams were measured on in-plane anisotropy Co60Fe20B20 magnetic tunnel junctions to obtain the spin transfer torque (STT) field-current switching window. These measurements used characterise with varying free layer thicknesses from 2.5 down 1.1 nm having a reduced effective demagnetizing field due perpendicular at CoFeB/MgO interface. Diagrams obtained 100 ns current pulses, of either same or alternating polarity. When consecutive pulses have polarity, it is possible...
Superconducting nanowire single photon detectors (SNSPDs) are a highly promising emerging counting technology, offering infrared sensitivity combined with low dark count rates and sub-100 ps timing jitter [1]. These devices under consideration for wide variety of applications, from quantum cryptography to remote sensing. Next generation device designs based on optical cavities, ultra narrow wires, parallel wire arrays nano-antenna enhanced being evaluated meet the demands advanced applications.
This work reports on advances in MRAM cells aiming at sub-nanosecond switching and for sub-20nm technology nodes. Ultrafast precessional spin-transfer elliptical magnetic tunnel junction nanopillars is possible to obtain samples integrating a perpendicular polarizer with in-plane magnetized electrodes. We show that spin transfer torque (STT) less than 500ps can be achieved these structures corresponding write energy 100fJ. For high density integration possibly diameter the use of thermally...