707 citations · 3.9k across the 61 of their papers we have counts for
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3D ferroelectric phase field simulations of polycrystalline multi-phase hafnia and zirconia based ultra-thin films
Prabhat Kumar, Michael Hoffmann, Andrew Nonaka +2
HfO- and ZrO-based ferroelectric thin films have emerged as promising candidates for the gate oxides of next generation electronic devices. Recent work has experimentally d…
Topological Edge Conduction Induced by Strong Anisotropic Exchange Interactions
Shehrin Sayed, Pratik Brahma, Cheng-Hsiang Hsu +1
We predict that an interplay between isotropic and anisotropic exchange interactions in a honeycomb lattice structure can lead to topological edge conduction when the anisotropic i…
Unified Framework for Charge-Spin Interconversion in Spin-Orbit Materials
Shehrin Sayed, Seokmin Hong, Xiaoxi Huang +5
Materials with spin-orbit coupling are of great interest for various spintronics applications due to the efficient electrical generation and detection of spin-polarized electrons.…
Spin-orbit torque generated by amorphous FeSi
Cheng-Hsiang Hsu, Julie Karel, Niklas Roschewsky +5
While tremendous work has gone into spin-orbit torque and spin current generation, charge-to-spin conversion efficiency remains weak in silicon to date, generally stemming from the…
Electric-Field Control of the Interlayer Exchange Coupling for Magnetization Switching
Shehrin Sayed, Cheng-Hsiang Hsu, Niklas Roschewsky +2
We propose an electric-field-controlled mechanism for magnetization switching assisted solely by the interlayer-exchange coupling (IEC) between the fixed and the free magnets, whic…
Spin-Orbit Torque and Nernst Effect in Bi-Sb/Co Heterostructures
Niklas Roschewsky, Emily S. Walker, Praveen Gowtham +4
Harmonic measurements of the longitudinal and transverse voltages in Bi-Sb/Co bilayers are presented. A large second harmonic voltage signal due to the ordinary Nernst effect is ob…
Ferroelectric Negative Capacitance Domain Dynamics
Michael Hoffmann, Asif Islam Khan, Claudy Serrao +6
Transient negative capacitance effects in epitaxial ferroelectric Pb(ZrTi)O capacitors are investigated with a focus on the dynamical switching behavior governe…
Differential voltage amplification from ferroelectric negative capacitance
Asif I. Khan, Michael Hoffmann, Korok Chatterjee +8
It is well known that one needs an external source of energy to provide voltage amplification. Because of this, conventional circuit elements such as resistors, inductors or capaci…
Negative Differential Resistance and Steep Switching in Chevron Graphene Nanoribbon Field Effect Transistors
Samuel Smith, Juan-Pablo Llinás, Jeffrey Bokor +1
Ballistic quantum transport calculations based on the non-equilbrium Green's function formalism show that field-effect transistor devices made from chevron-type graphene nanoribbon…
Thickness Dependence of Spin-Orbit Torques in Ferrimagnetic GdFeCo Alloys
Niklas Roschewsky, Charles-Henri Lambert, Sayeef Salahuddin
So far, studies of spin-orbit torques (SOT) in ferromagnets with perpendicular magnetic anisotropy (PMA) have been restricted to ultra thin samples, while a systematic study of its…
Single shot ultrafast all optical magnetization switching of ferromagnetic Co/Pt multilayers
Jon Gorchon, Charles-Henri Lambert, Yang Yang +4
In a number of recent experiments, it has been shown that femtosecond laser pulses can control magnetization on picosecond timescales, which is at least an order of magnitude faste…
Ultrafast Magnetization Reversal by Picosecond Electrical Pulses
Yang Yang, R. B. Wilson, Jon Gorchon +3
The field of spintronics involves the study of both spin and charge transport in solid state devices with a view toward increasing their functionality and efficiency. Alternatively…
Electric Current Induced Ultrafast Demagnetization
R. B. Wilson, Yang Yang, Jon Gorchon +3
We report the magnetic response of Co/Pt multilayers to picosecond electrical heating. Using photoconductive Auston switches, we generate electrical pulses with 5.5 picosecond dura…
Spin-Orbit Torques in ferrimagnetic GdFeCo Alloys
Niklas Roschewsky, Tomoya Matsumura, Suraj Cheema +4
The spin-orbit torque switching of ferrimagnetic Gd(FeCo) films was studied for both transition metal (TM)-rich and rare earth (RE)-rich configurations.…
Negative Capacitance in a Ferroelectric Capacitor
Asif Islam Khan, Korok Chatterjee, Brian Wang +6
The Boltzmann distribution of electrons poses a fundamental barrier to lowering energy dissipation in conventional electronics, often termed as Boltzmann Tyranny. Negative capacita…
Non-volatile Spin Switch for Boolean and Non-Boolean Logic
Supriyo Datta, Sayeef Salahuddin, Behtash Behin-Aein
We show that the established physics of spin valves together with the recently discovered giant spin-Hall effect could be used to construct Read and Write units that can be integra…
Dissipative Transport in Rough Edge Graphene Nanoribbon Tunnel Transistors
Youngki Yoon, Sayeef Salahuddin
We have studied quantum transport in Graphene Nanoribbon Tunnel Field-Effect Transistors. Unlike other studies on similar structures, we have included dissipative processes induced…
Intrinsic Cut-off Frequency in Scaled Graphene Transistors
Kartik Ganapathi, Youngki Yoon, Sayeef Salahuddin
Using 2-D self-consistent ballistic quantum transport simulations, we investigate the short-channel behavior of graphene field-effect transistors and its impact on the device trans…
Role of Phonon Scattering in Graphene Nanoribbon Transistors: Non-Equilibrium Green's Function Method with Real Space Approach
Youngki Yoon, Dmitri E. Nikonov, Sayeef Salahuddin
Mode space approach has been used so far in NEGF to treat phonon scattering for computational efficiency. Here we perform a more rigorous quantum transport simulation in real space…
Experimental Evidence of Ferroelectric Negative Capacitance in Nanoscale Heterostructures
Asif Islam Khan, Debanjan Bhowmik, Pu Yu +4
We report a proof-of-concept demonstration of negative capacitance effect in a nanoscale ferroelectric-dielectric heterostructure. In a bilayer of ferroelectric, Pb(Zr0.2Ti0.8)O3 a…
Heterojunction Vertical Band-to-Band Tunneling Transistors for Steep Subthreshold Swing and High ON Current
Kartik Ganapathi, Sayeef Salahuddin
We propose a Heterojunction Vertical Tunneling FET and show using self-consistent ballistic quantum transport simulations that it can provide very steep subthreshold swings and hig…
Barrier-Free Tunneling in a Carbon Heterojunction Transistor
Youngki Yoon, Sayeef Salahuddin
Recently it has been experimentally shown that a graphene nanoribbon (GNR) can be obtained by unzipping a carbon nanotube (CNT). This makes it possible to fabricate all-carbon hete…
Analysis of InAs Vertical and Lateral Band-to-Band Tunneling Transistors: Leveraging Vertical Tunneling for Improved Performance
Kartik Ganapathi, Youngki Yoon, Sayeef Salahuddin
Using self-consistent quantum transport simulation on realistic devices, we show that InAs band-to-band Tunneling Field Effect Transistors (TFET) with a heavily doped pocket in the…
Voltage Asymmetry of Spin-Transfer Torques
Deepanjan Datta, Behtash Behin-Aein, Sayeef Salahuddin +1
We present a Non-Equilibrium Green's Function based model for spin torque transfer (STT) devices which provides quantitative agreement with experimentally measured (1) differential…