2018 New's Items

Materials Scientists Discover ‘Chiral Phonons’

February 1, 2018
Glenn Roberts Jr. | Berkeley Lab

A research team from the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has found the first evidence that a shaking motion in the structure of an atomically thin (2-D) material possesses a naturally occurring circular rotation.

This rotation could become the building block for a new form of information technology, and for the design of molecular-scale rotors to drive microscopic motors and machines.

The monolayer material, tungsten diselenide (WSe2), is already well-known for its unusual ability to sustain special electronic properties...

https://newscenter.lbl.gov/2018/02/01/scientists-discover-chiral-phonons-atomic-…

Glass-Into-Solar Panels Research Featured on ABC News

January 29, 2018
abc 7 News

BERKELEY, Calif. (KGO) -- A breakthrough by a UC Berkeley professor at Lawrence Berkeley National Laboratory could one day help tall buildings use dramatically less energy, by using their windows to generate electricity.

The research, funded by the U.S. Department of Energy, comes from the lab of chemistry professor Peidong Yang, who showed us some small squares of orange-tinted glass. One was hooked up to electrodes under a microscope, with a bright light shining on it.

"At a lower temperature, they are transparent," he said. "Basically, they are windows, transparent windows...

https://abc7news.com/smart-glass-uc-berkeley-that-helps-buildings-use-less-energ…

Scientists Discover Material Ideal for Smart Photovoltaic Windows

January 22, 2018
Julie Chao | Berkeley Lab

Smart windows that are transparent when it’s dark or cool but automatically darken when the sun is too bright are increasingly popular energy-saving devices. But imagine that when the window is darkened, it simultaneously produces electricity. Such a material – a photovoltaic glass that is also reversibly thermochromic – is a green technology researchers have long worked toward, and now, scientists at Lawrence Berkeley National Laboratory (Berkeley Lab) have demonstrated a way to make it work.

Researchers at Berkeley Lab, a Department of Energy (DOE) national lab, discovered that a...

https://newscenter.lbl.gov/2018/01/22/scientists-discover-material-ideal-smart-p…

Department of Energy Joins Quest to Develop Quantum Computers

January 10, 2018
Adrian Cho | Science

The U.S. Department of Energy (DOE) is joining the quest to develop quantum computers, devices that would exploit quantum mechanics to crack problems that overwhelm conventional computers. The initiative comes as Google and other companies race to build a quantum computer that can demonstrate "quantum supremacy" by beating classical computers on a test problem. But reaching that milestone will not mean practical uses are at hand, and the new $40 million DOE effort is intended to spur the development of useful quantum computing algorithms for its work in chemistry, materials science,...

https://www.science.org/content/article/after-years-avoidance-department-energy-…

ATP-dependent Force Generation and Membrane Scission by ESCRT-III and Vps4

J. Schöneberg
M. Pavlin
S. Yan
M. Righini
I. Lee
L. Carlson
A. Bahrami
D. Goldman
X. Ren
G. Hummer
C. Bustamante
J. Hurley
2018

The endosomal sorting complexes required for transport (ESCRTs) catalyze reverse-topology scission from the inner face of membrane necks in HIV budding, multivesicular endosome biogenesis, cytokinesis, and other pathways. We encapsulated ESCRT-III subunits Snf7, Vps24, and Vps2 and the AAA+ ATPase (adenosine triphosphatase) Vps4 in giant vesicles from which membrane nanotubes reflecting the correct topology of scission could be pulled. Upon ATP release by photo-uncaging, this system generated forces within the nanotubes that led to membrane scission in a manner dependent upon Vps4...

3D Covalent Organic Frameworks of Interlocking 1D Square Ribbons

Y. Liu
C. S. Diercks
Y. Ma
H. Lyu
C. Zhu
S. A. Alshmimri
S. Alshihri
O. M. Yaghi
2018

A new mode of mechanical entanglement in extended structures is described where 1D organic ribbons of corner-sharing squares are mutually interlocked to form 3D woven covalent organic framework-500, COF-500. Reaction of aldehyde-functionalized tetrahedral Cu(PDB)2PO2Ph2complexes (PDB = 4,4′-(1,10-phenanthroline-2,9-diyl)dibenzaldehyde) with rectangular tetratopic ETTBA (4′,4‴,4′′′′′,4′′′′‴-(ethene-1,1,2,2-tetrayl)tetrakis([1,1′-biphenyl]-4-amine)) linkers through imine condensation, yielded a crystalline...

Bioinspired Metal-Organic Framework Catalysts for Selective Methane Oxidation to Methanol

Baek J
Rungtaweevoranit B
Pei X
Park M
Fakra SC
Liu YS
Matheu R
Alshmimri SA
Alshehri S
Trickett CA
Somorjai GA
Yaghi OM
2018

Particulate methane monooxygenase (pMMO) is an enzyme that oxidizes methane to methanol with high activity and selectivity. Limited success has been achieved in incorporating biologically relevant ligands for the formation of such active site in a synthetic system. Here, we report the design and synthesis of metal–organic framework (MOF) catalysts inspired by pMMO for selective methane oxidation to methanol. By judicious selection of a framework with appropriate topology and chemical functionality, MOF-808 was used to postsynthetically install ligands bearing imidazole units for...

Studying rare nonadiabatic dynamics with transition path sampling quantum jump trajectories

A.J. Schile
D.T. Limmer
2018

We present a method to study rare nonadiabatic dynamics in open quantum systems using transition path sampling and quantum jump trajectories. As with applications of transition path sampling to classical dynamics, the method does not rely on prior knowledge of transition states or reactive pathways and thus can provide mechanistic insight into ultrafast relaxation processes in addition to their associated rates. In particular, we formulate a quantum path ensemble using the stochastic realizations of an unravelled quantum master equation, which results in trajectories that can be...

Nonlinear transport coefficients from large deviation functions

C.Y. Gao
D.T. Limmer
2018

Nonlinear response occurs naturally when a strong perturbation takes a system far from equilibrium. Despite of its omnipresence in nanoscale systems, it is difficult to predict in a general and efficient way. Here we introduce a way to compute arbitrarily high order transport coefficients of stochastic systems, using the framework of large deviation theory. Leveraging time reversibility in the microscopic dynamics, we relate nonlinear response to equilibrium multi-time correlation functions among both time reversal symmetric and asymmetric observables, which can be evaluated from...

Elucidating CO2 Chemisorption in Diamine-Appended Metal-Organic Frameworks

A. C. Forse
P. J. Milner
J.-H. Lee
H. N. Redfearn
J. Oktawiec
R. L. Siegelman
J. D. Martell
B. Dinakar
L. B. Porter-Zasada
M. I. Gonzalez
J. B. Neaton
J. et. al
2018

The widespread deployment of carbon capture and sequestration as a climate change mitigation strategy could be facilitated by the development of more energy-efficient adsorbents. Diamine-appended metal–organic frameworks of the type diamine–M2(dobpdc) (M = Mg, Mn, Fe, Co, Ni, Zn; dobpdc4– = 4,4′-dioxidobiphenyl-3,3′-dicarboxylate) have shown promise for carbon-capture applications, although questions remain regarding the molecular mechanisms of CO2 uptake in these materials. Here we leverage the...