KNI Microscopy Seminar
Join the Kavli Nanoscience Institute for its next KNI Microscopy Seminar, a new series that brings internationally recognized microscopists to the KNI and Caltech.
This seminar will be given by Dr. Gregor Hlawacek (Head of the Ion Induced Nanostructures Group, Institute for Ion Beam Physics and Materials Research, Helmholtz—Zentrum Dresden—Rossendorf in Dresden, Germany). Light refreshments will be available beforehand.
"Application of gas field ion source and liquid metal alloy ion source-based focused ion beams"
I will present recent results obtained in our group using gas field ion sources (GFIS) and liquid metal alloy ion source (LMAIS) based focused ion beams (FIB). I will briefly explain the source technology and our efforts in developing new and unconventional ion sources for their application in FIB instruments. A few selected examples will include the LMAIS based fabrication of single photon emitters (SPE) which are fundamental building blocks for future quantum technology applications. I will present a method to fabricate at will placed single or few SPEs emitting in the telecom O-band in Silicon. The successful integration of these telecom quantum emitters into photonic structures such as micro-resonators, nanopillars and photonic crystals with sub-micrometer precision paves the way toward a monolithic, all-silicon-based semiconductor-superconductor quantum circuit for which this work lays the foundations. To achieve our goal we employ home built AuSi and a unique CeC LMAIS both operated in an Orsay Physics CANION M31Z+ FIB. Silicon-on-insulator substrates from different fabrication methods have been irradiated with a spot pattern. The achieved lateral SPE placement accuracy is below 100nm in both cases and the success rate of SPE formation is more than 50%. In addition I will present recent results obtained on the helium ion microscope using FIB and He ion extracted from a GFIS source. These examples will include the epitaxial over growth of Sn spheres during He ion beam irradiation. This more fundamental experiment show cases the importance of the ion beam driven generation of interstitials and their diffusion during the ion beam irradiation. Finally, I'd like to demonstrate how GFIS based HIM can be used to generate electrically controlled magnetic landscapes in spin orbit torque (SOT) materials. Here, we use in-situ controlled irradiation to identify the best irradiation conditions for the preparation of μm sized areas which will switch magnetization direction at different SOT currents.
Dr. Gregor Hlawacek is the head of the Ion Induced Nanostructures Group at the Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf. Gregor does research in Materials Science, Materials Physics and Experimental Physics in particular Ion solid interactions for high resolution imaging and nano-engineering. His work is focused in Helium Ion Microscopy and other FIB techniques. Dr. Hlawacek received his Ph.D. in Surface Science and Materials Science from the University of Leoben. His work has been published in Science, Nano Letters, PRB, Advanced Materials, among others.
NOTE: This is an in-person event. All attendees are required to follow campus Covid safety guidelines.