Bulletin of the American Physical Society
Far West Section Fall 2021 Meeting
Volume 66, Number 12
Friday–Saturday, October 29–30, 2021; Virtual
Session E01: Condensed Matter -1 |
Hide Abstracts |
Chair: Hope Ishii, University of Hawaii |
Friday, October 29, 2021 1:00PM - 1:12PM |
E01.00001: Resistivity of Doped Filled Skutterudite Compounds: Ce$_{1-x}$Pr$_x$ Os$_4$Sb$_{12}$ Leticia Ramos, Xingyu Zhao, Zachary Carrender, Pei-Chun Ho Filled skutterudite compounds are described by the chemical formula: LnT$_{4}$Pn$_{12}$ where Ln is a rare-earth metal, T is a transition metal, and Pn is a pnictogen. CeOs$_{4}$Sb$_{12}$ is a Kondo insulator that exhibits antiferromagnetism due to spin-density wave formation below 1 K. Based on the band-structure calculation, CeOs$_{4}$Sb$_{12}$ is suggested to be a candidate for topological insulators [1], which may have a hole Fermi surface and an electron Fermi surface coexisting at low temperatures. Through our previous study of CeOs$_{4}$Sb$_{12}$ [2,3], we found that the valence transition may occur in this compound, and we have established an intriguing temperature, $T$-, magnetic field, $H$, phase diagram in its normal state. Nevertheless, the neighboring isostructural compound PrOs$_{4}$Sb$_{12}$ is a heavy-fermion superconductor with a transition temperature at 1.85 K. When Pr substitutes Ce in CeOs$_{4}$Sb$_{12}$, a hole-doping is introduced. We plan to study the series of Ce$_{1-x}$Pr$_x$ Os$_4$Sb$_{12}$ to investigate the influence of hole-doping to the valence transition. In this report, we will show the preliminary results of normal state resistivity of two concentrations: x$=$0.1 and x$=$0.2 from 300 K to 12 K at zero magnetic field. [1] B. Yan, et al., PRB 85, 165125 (2012). [2] K. Gotze, et al., PRB 101, 075102 \quad (2020). [3] P.-C. Ho, et al., PRB 94, 205140 (2016). [Preview Abstract] |
Friday, October 29, 2021 1:12PM - 1:24PM |
E01.00002: Localization in the1-Dimensional Fermi-Hubbard Model Sobhan Sayadpour, Ettore Vitali The ability to study quantum systems and to predict their behaviors starting from the fundamental equations of quantum mechanics is a significant challenge with extensive applications, including but not limited to condensed matter physics, atomic physics, and even quantum information. In this context, computer simulations provide valuable insight into investigating the behavior of complex systems. The objective of our computational experiment is to design and perform a Monte Carlo simulation of a collection of fermions moving in a lattice, modeling the behavior of electrons in a crystalline solid. Furthermore, we would like to study and assess a computational probe that can distinguish between a conductor and an insulator, just relying on the ground state physics. This study is particularly relevant in a strongly correlated system as most current approaches rely on response functions. These functions involve the entire manifold of the excited states of the system, thus making the theoretical and computational approach a formidable task. The computational ground state probes that we are studying measure how the fermions scatter relative to each other. The anticipated results will show how reliable and sensitive those probes are. [Preview Abstract] |
Friday, October 29, 2021 1:24PM - 1:36PM |
E01.00003: Interplay between Magnetism and Superconductivity of $Fe_{0.5\%}TaSe_2$ through Magnetotransport Dhan Bautista, Alex Liebman-Pelaez, James Analytis Intercalation of magnetic ions into highly-correlated electron systems often leads to novel properties emerging from the interactions between magnetism and other order parameters, such as superconductivity. Here, magnetotransport properties of $Fe_{0.5\%}TaSe_2$ have been measured as functions of both temperature and field, across a range of pressure. The Fe-doped compound exhibits an overall negative magnetoresistance, in contrast to the positive magnetoresistance of the pure $TaSe_2$ compound. In addition, an anomalous magnetic hysteresis is present in the doped sample at 2 K. Lastly, under pressure the Kondo effect, driven by spin-spin scattering at dopant sites, gives way to superconductivity. [Preview Abstract] |
Friday, October 29, 2021 1:36PM - 1:48PM |
E01.00004: Driving Ultrafast Spin and Energy Modulation in Quantum Well States via Photo-Induced Electric Fields Samuel Ciocys, Alessandra Lanzara The future of modern optoelectronics and spintronic devices relies on our ability to control the spin and charge degrees of freedom at timescale that can compete with traditional silicon-based devices, operating at speeds greater than 10 GHz. Rashba spin-split quantum well states, 2D states that develop at the surface of strong spin-orbit coupling materials, are ideal given the easy tunability of their energy and spin states. So far however, most studies have only demonstrated such control in a static way. In this study, we demonstrate ultrafast control of the spin and energy degrees of freedom of surface quantum well states on Bi$_{2}$Se$_{3}$ at picosecond timescales. By means of a focused laser pulse, we modulate the band bending, producing picosecond time-varying electric fields at the material's surface, thereby reversibly modulating the quantum well spectrum and Rashba Effect. These results open a new pathway for light-driven spintronic devices with ultrafast switching of electronic phases, and offer the interesting prospect to extend this ultrafast photogating technique to a broader host of 2D materials. [Preview Abstract] |
Friday, October 29, 2021 1:48PM - 2:00PM |
E01.00005: Gap Dynamics in TiSe2 Maximilian Huber, Yi Lin, Robert Kaindl, Alessandra Lanzara TiSe2 is an intriguing material that hosts a charge density wave (CDW) phase below 200K in the absence of the prototypical Fermi surface nesting and that becomes superconducting at elevated pressures or by Cu doping. The key to understand the emergence of such correlated behavior is the order parameter, which can be directly accessed by measuring the CDW gap. Here we use time and angular resolved photoelectron spectroscopy (trARPES) to perturb the CDW phase in TiSe2 and follow the quench and recovery of the order parameter. The fluence dependence of the gap is discussed and its implication for the CDW formation mechanism are presented.~ [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