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Publications

Tunable shear thickening in suspensions

Cornell Affiliated Author(s)
Author
N.Y.C. Lin
C. Ness
M.E. Cates
J. Sun
Itai Cohen
Abstract

Shear thickening, an increase of viscosity with shear rate, is a ubiquitous phenomenon in suspended materials that has implications for broad technological applications. Controlling this thickening behavior remains a major challenge and has led to empirical strategies ranging from altering the particle surfaces and shape to modifying the solvent properties. However, none of these methods allows for tuning of flow properties during shear itself.

Journal
Proceedings of the National Academy of Sciences of the United States of America
Date Published
Funding Source
1232666
1509308
EP/N025318/1
DMR-1120296
EP/J007404
Group (Lab)
Itai Cohen Group

All-optical vector measurement of spin-orbit-induced torques using both polar and quadratic magneto-optic Kerr effects

Cornell Affiliated Author(s)
Author
Xin Fan
Alex Mellnik
Wenrui Wang
Neal Reynolds
Tao Wang
Halise Celik
Virginia Lorenz
Daniel Ralph
John Xiao
Abstract

We demonstrate that the magneto-optic-Kerr effect with normal light incidence can be used to obtain quantitative optical measurements of both components of spin-orbit-induced torque (both the antidamping and effective-field components) in heavy-metal/ferromagnet bilayers. This is achieved by analyzing the quadratic Kerr effect as well as the polar Kerr effect. The two effects can be distinguished by properly selecting the polarization of the incident light.

Journal
AIP Publishing
Date Published
Funding Source
DMR-1120296
DMR-1505192
DMR-1010768
ECCS-0335765
N66001-11-1-4110

The Chd1 chromatin remodeler can sense both entry and exit sides of the nucleosome

Cornell Affiliated Author(s)
Author
I.M. Nodelman
K.C. Horvath
R.F. Levendosky
J. Winger
R. Ren
A. Patel
M. Li
M.D. Wang
E. Roberts
G.D. Bowman
Abstract

Chromatin remodelers are essential for establishing and maintaining the placement of nucleosomes along genomic DNA. Yet how chromatin remodelers recognize and respond to distinct chromatin environments surrounding nucleosomes is poorly understood. Here, we use Lac repressor as a tool to probe how a DNA-bound factor influences action of the Chd1 remodeler. We show that Chd1 preferentially shifts nucleosomes away from Lac repressor, demonstrating that a DNA-bound factor defines a barrier for nucleosome positioning.

Journal
Nucleic Acids Research
Date Published
Research Area
Group (Lab)
Michelle Wang Group

Shubnikov-de Haas quantum oscillations reveal a reconstructed Fermi surface near optimal doping in a thin film of the cuprate superconductor Pr1.86Ce0.14CuO4±δ

Cornell Affiliated Author(s)
Author
Nicholas Breznay
Ian Hayes
B. Ramshaw
Ross McDonald
Yoshiharu Krockenberger
Ai Ikeda
Hiroshi Irie
Hideki Yamamoto
James Analytis
Abstract

We study magnetotransport properties of the electron-doped superconductor Pr2-xCexCuO4±δ with x=0.14 in magnetic fields up to 92 T, and observe Shubnikov-de Haas magnetic quantum oscillations. The oscillations display a single frequency F=255±10 T, indicating a small Fermi pocket that is ∼1% of the two-dimensional Brillouin zone and consistent with a Fermi surface reconstructed from the large holelike cylinder predicted for these layered materials.

Journal
Physical Review B
Date Published
Funding Source
DMR-1157490
DE-AC02-05CH11231
1157490
GBMF4374
Group (Lab)
Brad Ramshaw Group

Evolution of electronic correlations across the rutile, perovskite, and Ruddelsden-Popper iridates with octahedral connectivity

Cornell Affiliated Author(s)
Author
J.K. Kawasaki
M. Uchida
H. Paik
D.G. Schlom
K.M. Shen
Abstract

The confluence of electron correlations and spin-orbit interactions is critical to realizing quantum phases in 5d transition metal oxides. Here, we investigate how the strength of the effective electron correlations evolve across a series of d5 iridates comprised of IrO6 octahedra, ranging from the layered correlated insulator Sr2IrO4, to the three-dimensional perovskite semimetal SrIrO3, to metallic rutile IrO2 in which the octahedra are arranged in a mixed edge and corner sharing network.

Journal
Physical Review B
Date Published
Funding Source
DMR-1120296
15H05425
Group (Lab)
Kyle Shen Group

Scanning SQUID susceptometers with sub-micron spatial resolution

Cornell Affiliated Author(s)
Author
John Kirtley
Lisa Paulius
Aaron Rosenberg
Johanna Palmstrom
Connor Holland
Eric Spanton
Daniel Schiessl
Colin Jermain
Jonathan Gibbons
Y.-K.-K. Fung
Martin Huber
Daniel Ralph
Mark Ketchen
Gerald Gibson
Kathryn Moler
Abstract

Superconducting QUantum Interference Device (SQUID) microscopy has excellent magnetic field sensitivity, but suffers from modest spatial resolution when compared with other scanning probes. This spatial resolution is determined by both the size of the field sensitive area and the spacing between this area and the sample surface. In this paper we describe scanning SQUID susceptometers that achieve sub-micron spatial resolution while retaining a white noise floor flux sensitivity of ≈2μΦ0/Hz1/2.

Journal
AIP Publishing
Date Published
Funding Source
0957616
1120296
1406333
DGE-114747
DMR-0957616
DMR-1406333
DMR-1120296
ECCS-1542081

Tunable phonon-cavity coupling in graphene membranes

Cornell Affiliated Author(s)
Author
R. De Alba
F. Massel
I.R. Storch
T.S. Abhilash
A. Hui
P.L. McEuen
H.G. Craighead
J.M. Parpia
Abstract

A major achievement of the past decade has been the realization of macroscopic quantum systems by exploiting the interactions between optical cavities and mechanical resonators. In these systems, phonons are coherently annihilated or created in exchange for photons. Similar phenomena have recently been observed through phonon-cavity coupling - energy exchange between the modes of a single system mediated by intrinsic material nonlinearity.

Journal
Nature Nanotechnology
Date Published
Funding Source
DMR-1120296
ECCS-15420819
Group (Lab)
Jeevak Parpia Group
Paul McEuen Group

Scaling ansatz for the jamming transition

Cornell Affiliated Author(s)
Author
C.P. Goodrich
A.J. Liu
J.P. Sethna
Abstract

We propose a Widom-like scaling ansatz for the critical jamming transition. Our ansatz for the elastic energy shows that the scaling of the energy, compressive strain, shear strain, system size, pressure, shear stress, bulk modulus, and shear modulus are all related to each other via scaling relations, with only three independent scaling exponents. We extract the values of these exponents from already known numerical or theoretical results, and we numerically verify the resulting predictions of the scaling theory for the energy and residual shear stress.

Journal
Proceedings of the National Academy of Sciences of the United States of America
Date Published
Funding Source
1312160
Group (Lab)
James Sethna Group

Featureless quantum insulator on the honeycomb lattice

Cornell Affiliated Author(s)
Author
Panjin Kim
Hyunyong Lee
Shenghan Jiang
Brayden Ware
Chao-Ming Jian
Michael Zaletel
Jung Han
Ying Ran
Abstract

We show how to construct fully symmetric states without topological order on a honeycomb lattice for S=12 spins using the language of projected entangled pair states. An explicit example is given for the virtual bond dimension D=4. Four distinct classes differing by lattice quantum numbers are found by applying the systematic classification scheme introduced by two of the authors [S. Jiang and Y. Ran, Phys. Rev. B 92, 104414 (2015)PRBMDO1098-012110.1103/PhysRevB.92.104414].

Journal
Physical Review B
Date Published
Funding Source
DMR-1151440
NSF PHY11-25915
2015R1D1A1A01059296
Group (Lab)
Chao-Ming Jian Group

Gate Tuning of Electronic Phase Transitions in Two-Dimensional NbSe2

Cornell Affiliated Author(s)
Author
X. Xi
H. Berger
L. Forró
J. Shan
K.F. Mak
Abstract

Recent experimental advances in atomically thin transition metal dichalcogenide (TMD) metals have unveiled a range of interesting phenomena including the coexistence of charge-density-wave (CDW) order and superconductivity down to the monolayer limit. The atomic thickness of two-dimensional (2D) TMD metals also opens up the possibility for control of these electronic phase transitions by electrostatic gating. Here, we demonstrate reversible tuning of superconductivity and CDW order in model 2D TMD metal NbSe2 by an ionic liquid gate.

Journal
Physical Review Letters
Date Published
Funding Source
DMR-1410407
Group (Lab)
Jie Shan Group
Kin Fai Mak Group