Bulletin of the American Physical Society
2019 Joint Fall Meeting of the Texas Sections of APS, AAPT and Zone 13 of the SPS
Volume 64, Number 18
Friday–Saturday, October 25–26, 2019; Lubbock, Texas
Session F02: Condensed Matter, Nanoscience and Computational Physics II |
Hide Abstracts |
Chair: Charley Myles, Texas Tech University Room: Student Union Building Canyon Room |
Friday, October 25, 2019 4:00PM - 4:36PM |
F02.00001: Physics in Food Manufacture. Invited Speaker: John Bows Food and drink manufacturing is by far the single biggest manufacturing sector in the UK, supporting 3 million jobs and doubling exports in the last 10 years. Food manufacturing around the world can and does provide solutions to global challenges such as health and wellness (obesity, malnutrition), climate change, water shortages and food waste. Yet the role of science - and in particular physics - solving such challenges, as well as underpinning delicious, nutritious and safe food and beverages, is not well understood and certainly under-exploited. Physics academia in general lacks awareness of the exciting challenges food manufacturing provides and the societal impact in solving them This presentation reviews how physics and a physicists approach is at the core of solving food manufacturing challenges and underpins many food innovations. [Preview Abstract] |
Friday, October 25, 2019 4:36PM - 4:48PM |
F02.00002: Raman Signature of Layer Number and Crystal Quality of Chromium Triiodide Gaihua Ye, Zhipeng Ye, Eric Wauer, Fabin Diaz, David Tauzin, Rui He, Hyun Kim, Bowen Yang, Adam Tsen, Wencan Jin, Liuyan Zhao Chromium triiodide (CrI$_{\mathrm{3}})$ has recently been shown to host Ising ferromagnetism down to the monolayer limit, which stimulates numerous ideas of device applications based on this two-dimensional (2D) ferromagnet. We performed polarized Raman spectroscopy studies on phonon modes as a function of CrI$_{\mathrm{3}}$ thickness and ambient exposure time. In pristine samples, Raman selection rules for intralayer phonons remain the same not only above and below the structural phase transition, but also in bulk and atomic layers. This indicates that the interlayer coupling plays a negligible role on the symmetry properties of intralayer phonons. Despite the consistency of selection rules between pristine bulk and thin layer CrI$_{\mathrm{3}}$, the ratio between the A$_{\mathrm{g}}$(C$_{\mathrm{3i}})$ and E$_{\mathrm{g}}$(C$_{\mathrm{3i}})$ modes, at \textasciitilde 128 and \textasciitilde 107 cm$^{\mathrm{-1}}$ respectively, is a good indicator for labeling the layer numbers at room temperature, while the frequency separations between the magnetic excitation modes and its neighboring A$_{\mathrm{g}}$ phonon modes serve as another thickness marker below magnetic phase transition temperature $T_{\mathrm{C}}$. Raman spectra from CrI$_{\mathrm{3}}$ crystals after moderate ambient exposure are indistinguishable from that of the pristine CrI$_{\mathrm{3}}$ at room temperature, but exhibit significant differences below $T_{\mathrm{C}}$ [Preview Abstract] |
Friday, October 25, 2019 4:48PM - 5:00PM |
F02.00003: Volatile Insulator-Metal Transition of VO$_{\mathrm{2}}$ Resistors as Artificial Neurons Zhen Xu, Zhaoyang Fan VO$_{\mathrm{2}}$ exhibits insulator-metal transition when its temperature reaches to \textasciitilde 68$^{\mathrm{o}}$C, with abrupt resistivity reduction by 4-5 orders of magnitudes. This transition is volatile, and VO$_{\mathrm{2}}$ will return to its insulator state when its temperature is reduced below the transition temperature. In this work, we show that VO$_{\mathrm{2}}$ two-terminal thin-film devices (resistors), when driven under electrical pulses, can be used to implement the leaky, integrate and fire function of spiking neurons based on their resistive switching. With given thermal capacity and thermal loss rate, VO$_{\mathrm{2}}$ devices exhibit firing time and relaxation time between the exciting pulse and the resistance switching. The integrating effect of small pulses can also trigger the insulator to metal transition (firing) from high resistance to low resistance. These characteristics suggest the potential using the volatile phase transition of VO$_{\mathrm{2}}$ for artificial spiking neurons. We will present our recent experimental results in this aspect. Simulation work based on resistor network will also be discussed, focusing on the dynamic formation of a conducting filament in VO$_{\mathrm{2}}$ film when driven by a train of small pulses. The simulation confirms the formation of this conducting path in a flashing process during a single pulse of the pulse train when the integrating effect of these pulses arrives the threshold. [Preview Abstract] |
Friday, October 25, 2019 5:00PM - 5:12PM |
F02.00004: Non-linear dynamics and simulation of VO$_{\mathrm{2}}$ oscillators for micro-electronics applications Milinda Pattanayak, Md Nadim F Hoque, Yong Zhao, Zhaoyang Fan, Ayrton A Bernussi Vanadium dioxide (VO$_{\mathrm{2}})$ is a promising electronic material for emerging technologies. VO$_{\mathrm{2}}$ undergoes a reversible phase transformation accompanied by several orders of magnitude change in resistivity and hysteresis. Such attributes are ideal for designing novel devices with tunable and reconfigurable characteristics. In this work we investigated two-terminal devices based on VO$_{\mathrm{2}}$ thin films. The fabricated devices exhibited large amplitude electrical relaxation oscillation under voltage actuation conditions. We developed a circuit equivalent model for the VO$_{\mathrm{2}}$ based system and excellent agreement between experiment and simulation was verified. We have also analyzed the non-linear dynamics in such systems by deriving the dynamical differential equations for the oscillator circuit. A phase portrait analysis for the VO$_{\mathrm{2}}$ relaxation oscillator is presented. [Preview Abstract] |
Friday, October 25, 2019 5:12PM - 5:24PM |
F02.00005: A control of localized surface phonon polariton resonance using metal/dielectric multilayer boundary Satyanarayana Kachiraju, Ivan Nekrashevich, Long Chang, Myoung-Hwan Kim We fabricated subwavelength grating of a metal/dielectric multilayer on silicon carbide. We experimentally demonstrated a single, well-defined, control of localized surface phonon polariton resonance showing near perfect infrared absorption at the optical phonon band of silicon carbide. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700