OSE Seminar Series by Dr. Abdelghani Laraoui on Spin waves: from magnon spintronics to coupling spin qubits in diamond
Posted: March 29, 2019
Date: Thursday, April 4, 2019
Time: 11:00 AM to Noon
Location: CHTM, Room 101
Map to CHTM:
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Dr. Abdelghani Laraoui
Spin waves are dynamic magnetic excitations of a magnetically ordered system. They can be generated by injecting current or microwave, heating up the magnetic material, or exciting it with ultrashort laser pulses. They are already being explored for classical data transport, information storage, and low-energy logical operations. In this talk, I will discuss two applications of spin waves. First, by using Brillouin Light Scattering microscopy, we studied the spatial emission of spin waves induced by injecting a direct current through spin-valve nano-contacts (size < 80 nm). Large current densities can be achieved in the nanocontact area allowing the excitation of nonlinear spin waves, and their efficiency can be enhanced or reduced due to the spin transfer torque effect. This is first step toward the emerging field of magnon spintronics. Then I will explore spinwave-hosting ferromagnetic waveguides as quantum buses to couple distant spin qubits for scalable quantum platform. In particular I will show that magnetostatic surface spin-wave modes excited in yttrium iron garnet disks produce a dramatic amplification of a microwave field created by an adjacent 15-um Au wire. We used this spin-wave-mediated amplification to coherently control nitrogen vacancy center spin qubits in diamond located up to 3 mm away from the microwave source, one order of magnitude further than in previous experiments. The platform has proved to be highly efficient and may enable future applications in spin-based quantum architectures and remote sensing of target electron and nuclear spins.
Dr. Laraoui is a Research Assistant Professor at Center for High Technology Materials- University of New Mexico since September 2016. He earned his PhD in Physics from Louis Pasteur University of Strasbourg (France) where he developed a time resolved magneto-optical microscope to study the magnetization dynamics of magnetic nanomaterials excited with femtosecond laser pulses. Soon after his graduation, Dr. Laraoui received a Marie Curie fellowship from the European Research Training Network to carry a postdoctoral position at the University of Kaiserslautern (Germany). He used Brillouin Light Scattering Microscopy to study the spin current induced spin-wave emission in spin-torque nano-oscillators for applications in spintronics. After that, Dr. Laraoui joined CUNY-City College of New York as a research associate to work on a methodology to use the spin of nitrogen vacancy center (NVC) in diamond as a probe for high-resolution magnetic and temperature imaging at the nanoscale. Currently at CHTM, in collaboration with Prof. Acosta, Dr. Laraoui is developing new probes based on color centers in diamond and defects in wide-bandgap semiconductors for quantum sensing and nanoscale magnetic imaging. He is also exploring magnetic cavities and multiferroics for coupling distant spin-qubits for scalable quantum networks. Recently his research was funded by NSF and NIH.