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Publications

Dirac nodal lines protected against spin-orbit interaction in IrO2

Cornell Affiliated Author(s)
Author
J.N. Nelson
J.P. Ruf
Y. Lee
Cyrus Zeledon
J.K. Kawasaki
S. Moser
C. Jozwiak
E. Rotenberg
A. Bostwick
D.G. Schlom
K.M. Shen
L. Moreschini
Abstract

The interplay between strong spin-orbit coupling and electron correlations has recently been the subject of intense investigation, due to a number of theoretically predicted phases such as quantum spin liquids, unconventional superconductivity, complex magnetic orders, and correlated topological phases of matter. In particular, iridates have been proposed as a promising family of materials which could host a number of these phases.

Journal
Physical Review Materials
Date Published
Funding Source
DMR-1719875
1709255
1719875
DMR-1539918
DMR-1709255
Group (Lab)
Kyle Shen Group

Quantum simulation of the non-fermi-liquid state of Sachdev-Ye-Kitaev model

Cornell Affiliated Author(s)
Author
Zhihuang Luo
Yi-Zhuang You
Jun Li
Chao-Ming Jian
Dawei Lu
Cenke Xu
Bei Zeng
Raymond Laflamme
Abstract

The Sachdev-Ye-Kitaev (SYK) model incorporates rich physics, ranging from exotic non-Fermi liquid states without quasiparticle excitations, to holographic duality and quantum chaos. However, its experimental realization remains a daunting challenge due to various unnatural ingredients of the SYK Hamiltonian such as its strong randomness and fully nonlocal fermion interaction. At present, constructing such a nonlocal Hamiltonian and exploring its dynamics is best through digital quantum simulation, where state-of-the-art techniques can already handle a moderate number of qubits.

Journal
npj Quantum Information
Date Published
Funding Source
1151208
11605005
11875159
GBMF4304
U1801661
2016ZT06D348
11374032
11734002
11805008
JCYJ20170412152620376
ZDSYS20170303165926217
Group (Lab)
Chao-Ming Jian Group

Exceptionally High, Strongly Temperature Dependent, Spin Hall Conductivity of SrRuO

Cornell Affiliated Author(s)
Author
Yongxi Ou
Zhe Wang
Celesta Chang
Hari Nair
Hanjong Paik
Neal Reynolds
Daniel Ralph
David Muller
Darrell Schlom
Robert Buhrman
Abstract

Spin-orbit torques (SOT) in thin film heterostructures originate from strong spin-orbit interactions (SOI) that, in the bulk, generate a spin current due either to extrinsic spin-dependent, skew, or/and side-jump scattering or to intrinsic Berry curvature in the conduction bands. While most SOT studies have focused on materials with heavy metal components, the oxide perovskite SrRuO3 has been predicted to have a pronounced Berry curvature.

Journal
American Chemical Society (ACS)
Date Published
Funding Source
DMR-1719875
ECCS-1542081
DE-SC0002334

Enhancing Spin-Orbit Torque by Strong Interfacial Scattering From Ultrathin Insertion Layers

Cornell Affiliated Author(s)
Author
Lijun Zhu
Lujun Zhu
Shengjie Shi
Manling Sui
D.C. Ralph
Robert Buhrman
Abstract

Increasing dampinglike spin-orbit torque (SOT) is of fundamental importance for enabling new research into spintronics phenomena and also technologically urgent for advancing low-power spin-torque memory, logic, and oscillator devices. Here, we demonstrate that enhancing interfacial scattering by inserting ultrathin layers within spin Hall metals with intrinsic or side-jump mechanisms can significantly enhance the spin Hall ratio.

Journal
American Physical Society (APS)
Date Published
Funding Source
DMR-1719875
2019JQ-433
N00014-15-1-2449
GK201903024
W911NF-14-C0089
ECCS-1542081

Magnetic field-induced pair density wave state in the cuprate vortex halo

Cornell Affiliated Author(s)
Author
S.D. Edkins
A. Kostin
K. Fujita
A.P. Mackenzie
H. Eisaki
S. Uchida
S. Sachdev
M.J. Lawler
Eun-Ah Kim
J.C. Davis
M.H. Hamidian
Abstract

High magnetic fields suppress cuprate superconductivity to reveal an unusual density wave (DW) state coexisting with unexplained quantum oscillations. Although routinely labeled a charge density wave (CDW), this DWstate could actually be an electron-pair density wave (PDW). To search for evidence of a field-induced PDW, we visualized modulations in the density of electronic states N(r) within the halo surrounding Bi2Sr2CaCu2O8 vortex cores.

Journal
Science
Date Published
Group (Lab)
J.C. Seamus Davis Group
Michael Lawler Group

Self-organization of stem cells into embryos: A window on early mammalian development

Cornell Affiliated Author(s)
Author
M.N. Shahbazi
E.D. Siggia
M. Zernicka-Goetz
Abstract

Embryonic development is orchestrated by robust and complex regulatory mechanisms acting at different scales of organization. In vivo studies are particularly challenging for mammals after implantation, owing to the small size and inaccessibility of the embryo. The generation of stem cell models of the embryo represents a powerful system with which to dissect this complexity. Control of geometry, modulation of the physical environment, and priming with chemical signals reveal the intrinsic capacity of embryonic stem cells to make patterns.

Journal
Science
Date Published
Funding Source
669198
R01GM101653
207415/Z/17/Z
Research Area

Evolution of interlayer and intralayer magnetism in three atomically thin chromium trihalides

Cornell Affiliated Author(s)
Author
H.H. Kim
B. Yang
S. Li
S. Jiang
C. Jin
Z. Tao
G. Nichols
F. Sfigakis
S. Zhong
C. Li
S. Tian
D.G. Cory
G.-X. Miao
J. Shan
K.F. Mak
H. Lei
K. Sun
L. Zhao
A.W. Tsen
Abstract

We conduct a comprehensive study of three different magnetic semiconductors, CrI3, CrBr3, and CrCl3, by incorporating both few-layer and bilayer samples in van der Waals tunnel junctions. We find that the interlayer magnetic ordering, exchange gap, magnetic anisotropy, and magnon excitations evolve systematically with changing halogen atom. By fitting to a spin wave theory that accounts for nearest-neighbor exchange interactions, we are able to further determine a simple spin Hamiltonian describing all three systems.

Journal
Proceedings of the National Academy of Sciences of the United States of America
Date Published
Funding Source
1749774
1807810
DMR-1749774
DMR-1807810
N00014-18-1-2368
ER17-13-199
RGPIN-2017-03815
11574394
11774423
11822412
NRF-2017K1A3A1A12073407
RGPIN-04178
2016YFA0300504
Group (Lab)
Jie Shan Group
Kin Fai Mak Group

Low-noise, low-power, event-driven read-out of counting Pixel Array Detectors

Cornell Affiliated Author(s)
Author
M. Hromalik
K. Burkey
T. Burns
B. Lin
K. Shanks
P. Purohit
H. Philipps
M. Tate
Sol Gruner
Abstract

This article describes a highly parallel event driven interface between a Pixel Array Detector (PAD) and its processing electronics. The method used was originally developed for the Field Programmable Gate Array (FPGA) X-ray Pixel Array detector to allow for real-time processing of X-ray image data on its processing FPGA. This interface potentially allows for entirely asynchronous data transfer off the detector at rates exceeding 110Gbps and operates without the need for a constantly running clock.

Conference Name
.
Date Published
Group (Lab)
Sol M. Gruner Group

Machine learning in electronic-quantum-matter imaging experiments

Cornell Affiliated Author(s)
Author
Y. Zhang
A. Mesaros
K. Fujita
S.D. Edkins
M.H. Hamidian
K. Ch’ng
H. Eisaki
S. Uchida
J.C.S. Davis
E. Khatami
Eun-Ah Kim
Abstract

For centuries, the scientific discovery process has been based on systematic human observation and analysis of natural phenomena1. Today, however, automated instrumentation and large-scale data acquisition are generating datasets of such large volume and complexity as to defy conventional scientific methodology. Radically different scientific approaches are needed, and machine learning (ML) shows great promise for research fields such as materials science2–5.

Journal
Nature
Date Published
Group (Lab)
J.C. Seamus Davis Group