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Publications

Materials Relevant to Realizing a Field-Effect Transistor Based on Spin–Orbit Torques

Cornell Affiliated Author(s)
Author
Phillip Dang
Zexuan Zhang
Joseph Casamento
Xiang Li
Jashan Singhal
Darrell Schlom
Daniel Ralph
Huili Xing
Debdeep Jena
Abstract

Spin-orbit torque (SOT) is a promising mechanism for writing magnetic memories, while field-effect transistors (FETs) are the gold-standard device for logic operation. The spin-orbit torque field-effect transistor (SOTFET) is a proposed device that couples an SOT-controlled ferromagnet to a semiconducting transistor channel via the transduction in a magnetoelectric multiferroic (MF). This allows the SOTFET to operate as both a memory and a logic device, but its realization depends on the choice of appropriate materials.

Journal
Institute of Electrical and Electronics Engineers (IEEE)
Date Published
Funding Source
E2CDA 1740286
NewLAW EFRI 1741694
DGE-1650441
1740286
1741694

Modeling and Circuit Design of Associative Memories With Spin–Orbit Torque FETs

Cornell Affiliated Author(s)
Author
Olalekan Afuye
Xiang Li
Felicia Guo
Debdeep Jena
Daniel Ralph
Alyosha Molnar
Huili Xing
Alyssa Apsel
Abstract

This article introduces a circuits model for a proposed spin-based device called a spin-orbit torque field-effect transistor (SOTFET) that can operate as a nonvolatile memory and logic device. The SOTFET utilizes an FET structure with a ferromagnetic-multiferroic (MF) gate-stack that enables read/compute and write functions to be isolated. This is achieved by a combination of a ferromagnetic layer that is programmable via spin-orbit torque coupled to an MF layer that also couples into the gate of a traditional FET.

Journal
Institute of Electrical and Electronics Engineers (IEEE)
Date Published
Funding Source
1740286
ECCS 1740286
2758.001
2758.002

Pressure-controlled interlayer magnetism in atomically thin CrI3

Cornell Affiliated Author(s)
Author
T. Li
S. Jiang
N. Sivadas
Z. Wang
Y. Xu
D. Weber
J.E. Goldberger
K. Watanabe
T. Taniguchi
C.J. Fennie
Fai Mak
J. Shan
Abstract

Stacking order can influence the physical properties of two-dimensional van der Waals materials1,2. Here we applied hydrostatic pressure up to 2 GPa to modify the stacking order in the van der Waals magnetic insulator CrI3. We observed an irreversible interlayer antiferromagnetic-to-ferromagnetic transition in atomically thin CrI3 by magnetic circular dichroism and electron tunnelling measurements. The effect was accompanied by a monoclinic-to-rhombohedral stacking-order change characterized by polarized Raman spectroscopy.

Journal
Nature Materials
Date Published
Funding Source
1719875
N00014-18-1-2368
W911NF-17-1-0605
DMR-1719875
DMR-1420451
WE6480/1
JPMJCR15F3
Group (Lab)
Jie Shan Group
Kin Fai Mak Group

Towards biological applications of nanophotonic tweezers

Cornell Affiliated Author(s)
Author
R.P. Badman
F. Ye
M.D. Wang
Abstract

Optical trapping (synonymous with optical tweezers) has become a core biophysical technique widely used for interrogating fundamental biological processes on size scales ranging from the single-molecule to the cellular level. Recent advances in nanotechnology have led to the development of ‘nanophotonic tweezers,’ an exciting new class of ‘on-chip’ optical traps. Here, we describe how nanophotonic tweezers are making optical trap technology more broadly accessible and bringing unique biosensing and manipulation capabilities to biological applications of optical trapping.

Journal
Current Opinion in Chemical Biology
Date Published
Research Area
Group (Lab)
Michelle Wang Group

Flight of the fruit fly

Cornell Affiliated Author(s)
Author
Itai Cohen
Abstract

There comes a time in each of our lives where we grab a thick section of the morning paper, roll it up and set off to do battle with one of nature's most accomplished aviators-the fly. If, however, instead of swatting we could magnify our view and experience the world in slow motion we would be privy to a world-class ballet full of graceful figure-eight wing strokes, effortless pirouettes, and astonishing acrobatics. After watching such a magnificent display, who among us could destroy this virtuoso? How do flies produce acrobatic maneuvers with such precision?

Journal
Physical Review Fluids
Date Published
Funding Source
1546710
61651-EG
ARO
1056662
DMR award
Research Area
Group (Lab)
Itai Cohen Group

The clot thickens: Autologous and allogeneic fibrin sealants are mechanically equivalent in an ex vivo model of cartilage repair

Cornell Affiliated Author(s)
Author
R.M. Irwin
L.J. Bonassar
Itai Cohen
A.M. Matuska
J. Commins
B. Cole
L.A. Fortier
Abstract

Fibrin sealants are commonly used in cartilage repair surgeries to adhere cells or grafts into a cartilage defect. Both autologous and commercial allogeneic fibrin sealants are used in cartilage repair surgeries, yet there are no studies characterizing and comparing the mechanical properties of fibrin sealants from all-autologous sources.

Journal
PLoS ONE
Date Published
Funding Source
5R01AR071394-02
R01AR071394
1536463
Research Area
Group (Lab)
Itai Cohen Group

Towards efficient and stable perovskite solar cells employing non-hygroscopic F4-TCNQ doped TFB as the hole-transporting material

Cornell Affiliated Author(s)
Author
H. Kwon
J.W. Lim
J. Han
L.N. Quan
D. Kim
E.-S. Shin
Eun-Ah Kim
D.-W. Kim
Y.-Y. Noh
I. Chung
D.H. Kim
Abstract

Designing an efficient and stable hole transport layer (HTL) material is one of the essential ways to improve the performance of organic-inorganic perovskite solar cells (PSCs). Herein, for the first time, an efficient model of a hole transport material (HTM) is demonstrated by optimized doping of a conjugated polymer TFB (poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)]) with a non-hygroscopic p-type dopant F4-TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) for high-efficiency PSCs.

Journal
Nanoscale
Date Published
Group (Lab)

Low temperature hidden Fermi-liquid charge transport in under doped LaxSr1-xCuO2 infinite layer electron-doped thin films

Cornell Affiliated Author(s)
Author
C. Sacco
A. Galdi
P. Orgiani
N. Coppola
H.I. Wei
R. Arpaia
S. Charpentier
F. Lombardi
B. Goodge
L.F. Kourkoutis
K. Shen
D.G. Schlom
L. Maritato
Abstract

We have studied the low temperature electrical transport properties of LaxSr1-xCuO2 thin films grown by oxide molecular beam epitaxy on (1 1 0) GdScO3 and TbScO3 substrates. The transmission electron microscopy measurements and the x-ray diffraction analysis confirmed the epitaxy of the obtained films and the study of their normal state transport properties, removing the ambiguity regarding the truly conducting layer, allowed to highlight the presence of a robust hidden Fermi liquid charge transport in the low temperature properties of infinite layer electron doped cuprate superconductors.

Journal
Journal of Physics Condensed Matter
Date Published
Funding Source
1719875
Group (Lab)
Kyle Shen Group

Ferroelectric properties of ion-irradiated bismuth ferrite layers grown via molecular-beam epitaxy

Cornell Affiliated Author(s)
Author
Antonio Mei
Sahar Saremi
Ludi Miao
Matthew Barone
Yongjian Tang
Cyrus Zeledon
Jürgen Schubert
Daniel Ralph
Lane Martin
Darrell Schlom
Abstract

We systematically investigate the role of defects, introduced by varying synthesis conditions and by carrying out ion irradiation treatments, on the structural and ferroelectric properties of commensurately strained bismuth ferrite BixFe2-xO3 layers grown on SrRuO3-coated DyScO3(110)o substrates using adsorption-controlled ozone molecular-beam epitaxy. Our findings highlight ion irradiation as an effective approach for reducing through-layer electrical leakage, a necessary condition for the development of reliable ferroelectrics-based electronics. © 2019 Author(s).

Journal
AIP Publishing
Date Published
Funding Source
1708615
1719875
1740286
SRC

Layer-dependent spin-orbit torques generated by the centrosymmetric transition metal dichalcogenide β−MoTe2

Cornell Affiliated Author(s)
Author
Gregory Stiehl
Ruofan Li
Vishakha Gupta
Ismail Baggari
Shengwei Jiang
Hongchao Xie
Lena Kourkoutis
Kin Mak
Jie Shan
Robert Buhrman
Daniel Ralph
Abstract

Single-crystal materials with sufficiently low crystal symmetry and strong spin-orbit interactions can be used to generate novel forms of spin-orbit torques on adjacent ferromagnets, such as the out-of-plane antidamping torque previously observed in WTe2/ferromagnet heterostructures. Here, we present measurements of spin-orbit torques produced by the low-symmetry material β-MoTe2, which, unlike WTe2, retains bulk inversion symmetry.

Journal
American Physical Society (APS)
Date Published
Funding Source
1429155
1542081
Group (Lab)
Jie Shan Group
Kin Fai Mak Group