MateriAlZ Seminar Series: Alexander A. Balandin
Friday, October 01, 2021, 11:00 am Arizona Time
Alexander A. Balandin
Distinguished Professor of Electrical and Computer Engineering and the University of California Presidential
Chair Professor of Materials Science at the University of California, Riverside
"Dimensional Charge-Density-Wave Quantum Materials and Devices"
Zoom link, passcode: 565830
Abstract
The charge-density-wave (CDW) phase is a quantum state consisting of a periodic modulation of the electronic charge density accompanied by a periodic distortion of the atomic lattice in metallic van der Waals crystals. Several 2D layered transition metal dichalcogenides exhibit unusually high transition temperatures to different CDW phases, opening the possibility for practical device applications. One of the most promising materials, 1T-TaS2, has the CDW transition between the nearly-commensurate (NC-CDW) and the incommensurate (IC-CDW) phases at 350 K. Balandin will discuss his experimental results on controlling the CDW phase transitions in 2D materials with an applied electric field, and outline possible device applications of 2D CDW materials. Specifically, he will describe the room-temperature voltage-controlled oscillators, which operate on the basis of the NC-to-IC CDW transition in the quasi-2D 1T-TaS2 channels triggered by an applied voltage [1-2]. He will discuss hardness against X-ray and proton radiations of 2D CDW devices [2-3], and the use of the low-frequency electronic noise spectroscopy for monitoring the CDW phase transitions [4-6]. The nature of the CDW switching in such devices, i.e. pure electric field vs. thermally driven phase transitions, and speed of CDW devices will also be discussed [7-8]. The work at UC Riverside was supported, in part, by the U.S. DOE, NSF DMREF and DOD VBFF.
[1] G. Liu, et al., Nature Nanotechnology, 11 (2016) 845; [2] G. Liu, et al., IEEE Electron Device Letters, 38 (2017) 1724; [3] A. K. Geremew, et al., Nanoscale, 11 (2019) 8380; [4] A. K. Geremew, et al., ACS Nano, 13 (2019) 7231; [5] R. Salgado, et al., Appl. Phys. Express, 12 (2019) 037001; [6] A. K. Geremew, et al., Appl. Phys. Lett., 116 (2020) 163101; [7] A. Mohammadzadeh, et al., Appl. Phys. Lett., 118 (2021) 093102; [8] A. Mohammadzadeh, et al., Appl. Phys. Lett., 118 (2021) 223101.
Bio
Alexander A. Balandin is a distinguished professor of Electrical and Computer Engineering, and the University of California presidential chair professor of Materials Science at the University of California, Riverside. His research expertise covers a wide range of nanotechnology, materials science, electronics, and phononics fields. He is a recipient of The MRS Medal from the Materials Research Society for the discovery of unique heat conduction properties of graphene and the Pioneer of Nanotechnology Award from IEEE Society for his nanophononics research. He is an elected fellow of MRS, APS, IEEE, OSA, SPIE, and AA AS; is among the Clarivate Analytics Highly Cited Researchers, and serves as deputy editor in chief of the Applied Physics Letters. Professor Balandin is a recipient of the Vannevar Bush Faculty Fellowship (class of 2021).