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Publications

Ordered mesoporous crystalline aluminas from self-assembly of ABC triblock terpolymer-butanol-alumina sols

Cornell Affiliated Author(s)
Author
K.W. Tan
H. Sai
S.W. Robbins
J.G. Werner
T.N. Hoheisel
S.A. Hesse
P.A. Beaucage
F.J. DiSalvo
Sol Gruner
M. Murtagh
U. Wiesner
Abstract

A one-pot synthesis approach is described to generate ordered mesoporous crystalline γ-alumina-carbon composites and ordered mesoporous crystalline γ-alumina materials via the combination of soft and hardlating chemistries using block copolymers as soft structure-directing agents. Periodically ordered alumina hybrid mesostructures were generated by self-assembly of a poly(isoprene)-block-poly(styrene)-block-poly(ethylene oxide) terpolymer, n-butanol and aluminum tri-sec-butoxide derived sols in organic solvents.

Journal
RSC Advances
Date Published
Group (Lab)
Sol M. Gruner Group

Pitch perfect: How fruit flies control their body pitch angle

Cornell Affiliated Author(s)
Author
S.C. Whitehead
T. Beatus
L. Canale
Itai Cohen
Abstract

Flapping insect flight is a complex and beautiful phenomenon that relies on fast, active control mechanisms to counter aerodynamic instability. To directly investigate how freely flying Drosophila melanogaster control their body pitch angle against such instability, we perturbed them using impulsive mechanical torques and filmed their corrective maneuvers with high-speed video.

Journal
Journal of Experimental Biology
Date Published
Funding Source
1056662
Research Area
Group (Lab)
Itai Cohen Group

Spectroscopic Imaging STM: Atomic-Scale Visualization of Electronic Structure and Symmetry in Underdoped Cuprates

Cornell Affiliated Author(s)
Author
K. Fujita
M. Hamidian
I. Firmo
S. Mukhopadhyay
C.K. Kim
H. Eisaki
S.-I. Uchida
J.C. Davis
Abstract

Atomically resolved spectroscopic imaging STM (SI-STM) has played a pivotal role in visualization of the electronic structure of cuprate high temperature superconductors. In both the d-wave superconducting (dSC) and the pseudogap (PG) phases of underdoped cuprates, two distinct types of electronic states are observed when using SI-STM.

Journal
Springer Series in Solid-State Sciences
Date Published
Group (Lab)
J.C. Seamus Davis Group

Density-wave instabilities of fractionalized Fermi liquids

Cornell Affiliated Author(s)
Author
Debanjan Chowdhury
S. Sachdev
Abstract

Recent experiments in the underdoped regime of the hole-doped cuprates have found evidence for an incommensurate charge density-wave state. We present an analysis of the charge ordering instabilities in a metal with antiferromagnetic correlations, where the electronic excitations are coupled to the fractionalized excitations of a quantum fluctuating antiferromagnet on the square lattice.

Journal
Physical Review B - Condensed Matter and Materials Physics
Date Published
Funding Source
DMR-1360789
1360789
Group (Lab)
Debanjan Chowdhury Group

Deterministic switching of ferromagnetism at room temperature using an electric field

Cornell Affiliated Author(s)
Author
J. Heron
J. Bosse
Q. He
Y. Gao
M. Trassin
L. Ye
J. Clarkson
C. Wang
Jian Liu
S. Salahuddin
D. Ralph
D. Schlom
J. Íñiguez
B. Huey
R. Ramesh
Abstract

The technological appeal of multiferroics is the ability to control magnetism with electric field1-3. For devices to be useful, such control must be achieved at room temperature. The only single-phase multiferroicmaterial exhibiting unambiguousmagnetoelectric coupling at room temperature is BiFeO3 (refs 4 and 5). Its weak ferromagnetismarises fromthe canting of the antiferromagnetically aligned spins by the Dzyaloshinskii-Moriya (DM) interaction6-9.

Journal
Springer Science and Business Media LLC
Date Published
Funding Source
DE-SC0005037
CSD2007-00041
MAT2010-18113
EEC-1160504
DE-AC02-05CH11231
W911NF-08-2-0032
DMR-1120296

Connecting high-field quantum oscillations to zero-field electron spectral functions in the underdoped cuprates

Cornell Affiliated Author(s)
Author
A. Allais
Debanjan Chowdhury
S. Sachdev
Abstract

The nature of the pseudogap regime of cuprate superconductors at low hole density remains unresolved. It has a number of seemingly distinct experimental signatures: a suppression of the paramagnetic spin susceptibility at high temperatures, low-energy electronic excitations that extend over arcs in the Brillouin zone, X-ray detection of charge-density wave order at intermediate temperatures and quantum oscillations at high magnetic fields and low temperatures.

Journal
Nature Communications
Date Published
Funding Source
DMR-1103860
DMR-1360789
1103860
1360789
W911NF-14-1-0003
Group (Lab)
Debanjan Chowdhury Group

Layer construction of 3D topological states and string braiding statistics

Cornell Affiliated Author(s)
Author
Chao-Ming Jian
Xiao-Liang Qi
Abstract

While the topological order in two dimensions has been studied extensively since the discovery of the integer and fractional quantum Hall systems, topological states in three spatial dimensions are much less understood. In this paper, we propose a general formalism for constructing a large class of threedimensional topological states by stacking layers of 2D topological states and introducing coupling between them.

Journal
Physical Review X
Date Published
Group (Lab)
Chao-Ming Jian Group

Superconducting proximity effect in topological metals

Cornell Affiliated Author(s)
Author
K. Lee
A. Vaezi
M.H. Fischer
Eun-Ah Kim
Abstract

Much interest in the superconducting proximity effect in three-dimensional (3D) topological insulators (TIs) has been driven by the potential to induce Majorana bound states at the interface. Most candidate materials for 3D TI, however, are bulk metals, with bulk states at the Fermi level coexisting with well-defined surface states exhibiting spin-momentum locking. In such topological metals, the proximity effect can differ qualitatively from that in TIs.

Journal
Physical Review B - Condensed Matter and Materials Physics
Date Published
Group (Lab)

Effects of enzymatic treatments on the depth-dependent viscoelastic shear properties of articular cartilage

Cornell Affiliated Author(s)
Author
D.J. Griffin
J. Vicari
M.R. Buckley
J.L. Silverberg
Itai Cohen
L.J. Bonassar
Abstract

Osteoarthritis (OA) is a disease that involves the erosion and structural weakening of articular cartilage. OA is characterized by the degradation of collagen and proteoglycans in the extracellular matrix (ECM), particularly at the articular surface by proteinases including matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs).1 Degradation of collagen and proteoglycans is known to alter shear mechanical properties of cartilage, but study of this phenomenon has been focused on bulk tissue properties.

Journal
Journal of Orthopaedic Research
Date Published
Funding Source
R21AR054867
Research Area
Group (Lab)
Itai Cohen Group