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Publications

Graphene as a protein crystal mounting material to reduce background scatter

Cornell Affiliated Author(s)
Author
J.L. Wierman
J.S. Alden
C.U. Kim
P.L. McEuen
Sol Gruner
Abstract

The overall signal-to-noise ratio per unit dose for X-ray diffraction data from protein crystals can be improved by reducing the mass and density of all material surrounding the crystals. This article demonstrates a path towards the practical ultimate in background reduction by use of atomically thin graphene sheets as a crystal mounting platform for protein crystals.

Journal
Journal of Applied Crystallography
Date Published
Group (Lab)
Paul McEuen Group
Sol M. Gruner Group

Simultaneous electrical and optical readout of graphene-coated high Q silicon nitride resonators

Cornell Affiliated Author(s)
Author
V.P. Adiga
R. De Alba
I.R. Storch
P.A. Yu
B. Ilic
R.A. Barton
S. Lee
J. Hone
P.L. McEuen
J.M. Parpia
H.G. Craighead
Abstract

Resonant mechanics of high quality factor (Q) graphene coated silicon nitride devices have been explored using optical and electrical transduction schemes. With the addition of the graphene layer, we retain the desirable mechanical properties of silicon nitride but utilize the electrical and optical properties of graphene to transduce and tune the resonant motion by both optical and electrical means.

Journal
Applied Physics Letters
Date Published
Funding Source
DMR 1120296
DMR-0908634
ECCS-1001742
FA9550-09-1-0705
Group (Lab)
Jeevak Parpia Group
Paul McEuen Group

Small Molecule Injection into Single-Cell C. elegans Embryos via Carbon-Reinforced Nanopipettes

Cornell Affiliated Author(s)
Author
L.D. Brennan
T. Roland
D.G. Morton
S.M. Fellman
S.Y. Chung
M. Soltani
J.W. Kevek
P.M. McEuen
K.J. Kemphues
M.D. Wang
Abstract

The introduction of chemical inhibitors into living cells at specific times in development is a useful method for investigating the roles of specific proteins or cytoskeletal components in developmental processes. Some embryos, such as those of Caenorhabditis elegans, however, possess a tough eggshell that makes introducing drugs and other molecules into embryonic cells challenging. We have developed a procedure using carbon-reinforced nanopipettes (CRNPs) to deliver molecules into C. elegans embryos with high temporal control.

Journal
PLoS ONE
Date Published
Funding Source
GM059849
GM79112
MCB-0820293
P40 OD010440
R01GM059849
Research Area
Group (Lab)
Michelle Wang Group
Paul McEuen Group

Observation and spectroscopy of a two-electron Wigner molecule in an ultraclean carbon nanotube

Cornell Affiliated Author(s)
Author
S. Pecker
F. Kuemmeth
A. Secchi
M. Rontani
D.C. Ralph
P.L. McEuen
S. Ilani
Abstract

Two electrons on a string form a simple model system where Coulomb interactions are expected to play an interesting role. In the presence of strong interactions, these electrons are predicted to form a Wigner molecule, separating to the ends of the string. This spatial structure is believed to be clearly imprinted on the energy spectrum, yet so far a direct measurement of such a spectrum in a controllable one-dimensional setting is still missing. Here we use an ultraclean carbon nanotube to realize this system in a tunable potential.

Journal
Nature Physics
Date Published
Funding Source
BSF 710647-03
DMR-1010768
EEC-0646547
2005/08-80.0
EECS-0335765
0646547
1010768
1120296
DMR-1120296
258753
IRG 239322
Group (Lab)
Paul McEuen Group

Hyperspectral imaging of structure and composition in atomically thin heterostructures

Cornell Affiliated Author(s)
Author
R.W. Havener
C.-J. Kim
L. Brown
J.W. Kevek
J.D. Sleppy
P.L. McEuen
J. Park
Abstract

Precise vertical stacking and lateral stitching of two-dimensional (2D) materials, such as graphene and hexagonal boron nitride (h-BN), can be used to create ultrathin heterostructures with complex functionalities, but this diversity of behaviors also makes these new materials difficult to characterize. We report a DUV-vis-NIR hyperspectral microscope that provides imaging and spectroscopy at energies of up to 6.2 eV, allowing comprehensive, all-optical mapping of chemical composition in graphene/h-BN lateral heterojunctions and interlayer rotations in twisted bilayer graphene (tBLG).

Journal
Nano Letters
Date Published
Group (Lab)
Paul McEuen Group

Strain solitons and topological defects in bilayer graphene

Cornell Affiliated Author(s)
Author
J.S. Alden
A.W. Tsen
P.Y. Huang
R. Hovden
L. Brown
J. Park
D.A. Muller
P.L. McEuen
Abstract

Bilayer graphene has been a subject of intense study in recent years. The interlayer registry between the layers can have dramatic effects on the electronic properties: for example, in the presence of a perpendicular electric field, a band gap appears in the electronic spectrum of so-called Bernal-stacked graphene [Oostinga JB, et al. (2007) Nature Materials 7:151-157]. This band gap is intimately tied to a structural spontaneous symmetry breaking in bilayer graphene, where one of the graphene layers shifts by an atomic spacing with respect to the other.

Journal
Proceedings of the National Academy of Sciences of the United States of America
Date Published
Funding Source
FA9550-09-1-0691
FA9550-10-1-0410
DGE-0707428
NSF DMR-1120296
Group (Lab)
Paul McEuen Group

Two-pulse space-time photocurrent correlations at graphene p-n junctions reveal hot carrier cooling dynamics near the fermi level

Cornell Affiliated Author(s)
Author
M.W. Graham
S. Shi
D.C. Ralph
J. Park
P.L. McEuen
Abstract

Two-pulse excitation at a graphene p-n junction generates a time-dependent photocurrent response that we show functions as a novel ultrafast thermometer of the hot electron temperature, Te(t). The extracted hot electron cooling rates are consistent with heat dissipation near the Fermi level of graphene occurring by an acoustic phonon supercollision mechanism. © Owned by the authors, published by EDP Sciences, 2013.

Conference Name
.
Date Published
Group (Lab)
Paul McEuen Group

Confined plasmons in graphene microstructures: Experiments and theory

Cornell Affiliated Author(s)
Author
J.H. Strait
P. Nene
W.-M. Chan
C. Manolatou
S. Tiwari
F. Rana
J.W. Kevek
P.L. McEuen
Abstract

Graphene, a two-dimensional material with a high mobility and a tunable conductivity, is uniquely suited for plasmonics. The frequency dispersion of plasmons in bulk graphene has been studied both theoretically and experimentally, but no theoretical models have been reported and tested against experiments for confined plasmon modes in graphene microstructures. In this Rapid Communication, we present measurements as well as analytical and computational models for such confined modes. We show that plasmon modes can be described by an eigenvalue equation.

Journal
Physical Review B - Condensed Matter and Materials Physics
Date Published
Funding Source
1120296
Group (Lab)
Paul McEuen Group

Graphene micro- and nano-plasmonics

Cornell Affiliated Author(s)
Author
P. Nene
J.H. Strait
W.-M. Chan
C. Manolatou
S. Tiwari
F. Rana
J.W. Kevek
P.L. McEuen
Abstract

We present experimental and theoretical results of confined plasmons in graphene micro- and nano-structures. We present a FDTD technique to accurately model the measured data and demonstrate the importance of interactions between plasmonic structures. © 2013 The Optical Society of America.

Conference Name
.
Date Published
Group (Lab)
Paul McEuen Group