u ~ coulomb band gap mott insulator 1.6 1.51.4 1.31.21.1 inter-particle coupling strong coupling...
Post on 22-Dec-2015
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U ~ Coulomb Band gap
Mott Insulator
1.6 1.5 1.4 1.3 1.2 1.1
RD
2
Inter-particle couplingStrong
couplingWeakcoupling
Metal-Insulator Transition
Quantum Dot Quantum Dot Designed SolidsDesigned Solids
Heath group contactsKris Beverly: [email protected] Chaudhari: Kristen Koch: Also: Raphy Levine, Francoise Remacle, and Jose SampaioFunding: CULAR; DOE
150 300
e17
e21
e25
Res
ista
nce
Temperature80
Ea from slope
280
320
360
acti
vati
on
en
erg
y (
K )
140 210 280area (cm2)
-1.0 0 1.0I(
nA
)
Volts
ND
OS
Single e phenomena
Cooperative phenomenaIn this project, we are trying to
develop quantum dot solids as model systems for understanding the elec-tronic properties of low-dimensional solids. At top left is a TEM image of a single monolayer of 7 nm diameter, organically passivated silver quantum dots, and this is our model system for study. At top right is a description of how the electronic properties of this superlattice vary as the interparticle separation distance is decreased (as quantum exchange coupling is turned on). When the particles are well isolated, the system is a Mott insulator, and exhibits single electron charging characteristics. When the particles are sufficiently close together, the system passes from an insulator to a metal. Then, as measured by DC transport, temperature dependence of the conductivity causes localization phenomena, which can be then quantified. The various curves at the bottom left reflect the temperature-dependent DC transport of such a superlattice as a function of interparticle separation distance.
A = 0 0 1 1B = 0 1 0 1
50
60
70
Cu
rren
t (1
0-9 A
mp
s)
A
B
A
B
SUM
Heath group contacts:Yi Luo: [email protected] Diehl: [email protected] DeIonno: [email protected] Ho: [email protected] Beckman: [email protected] Nick Melosh: [email protected] Wong: [email protected] Also: Fraser Stoddart Group &Hewlett Packard CorporationFunding: DARPA; SRC; NSF; ONR
Molecular ElectronicsMolecular Electronics
In this project we are trying to develop molecular electronics-based circuitry for computing applications. This project involves a broad range of scientific challenges, ranging from developing techniques for device scaling to a few nanometers length scale to computer architecture and molecular materials development. Clockwise, from top middle left: An artists version of a molecular switch tunnel junction using [2]catenane molecular switches. The central figure is a distorted micrograph of a 16-bit molecular memory circuit at device size of ~0.0025 microns 2. Right top center is data from a 16-bit molecular electronic random access memory circuit; far right is a [2]rotaxane molecular switch. Bottom right is a chemically assembled crossbar circuit using single-walled carbon nanotubes; bottom left is the truth table from an XOR molecular-based logic circuit; middle left is an artists depiction of a molecular electronic nanoscale crossbar.
Laser
Optical Layer
Nanofluidiclayer
SensorLayer
Sensors
Nanocell
Contact Pads
Valves
Micropumps
Waveguides
OpticalSplitter
Micromirror
Laser
Optical Layer
Nanofluidiclayer
SensorLayer
Sensors
Nanocell
Contact Pads
Valves
Micropumps
Waveguides
OpticalSplitter
Micromirror
Time (sec)0.00 0.05 0.10 0.15
Gat
ing
Cu
rren
t (A
mp
s)
0
2e-11
4e-11 VG = -10 mVVG = 100 mV
High throughput proteomics devices
Heath group contacts:Dr. Xin Yang [email protected] Dr. Hyeon Choi [email protected] Rigo Pantoja [email protected] Ryan Riess [email protected]: Francisco Bezanilla (UCLA medical school) & Rich Sayaklly (UC Berkeley)Funding: W.M. Keck Foundation
In this collaboration with the UCLA medical school, and with the School of Engineering, we are trying to develop bio-device platforms for the combinatorial interrogation of transmembrane proteins in highly controlled environments. At top left is a ‘protein’ chip consisting of a lipid bilayer suspended across a pore micromachined into a silicon wafer. Voltage gating of the membrane reveals single channel protein gating characteristics. At top right is our targetted device: a library of cellular membranes in which we utilize fluidics, electronics, sensors, and optics to interrogate the proteins in a host of chemical and physical environments. At bottom left is a picture of a scanning non=linear optical microscope that we have constructed for this project. This microscope utilizes femtosecond laser exciation pulses, and collects the second harmonic generation signal and the two-photon fluorescence signal while retaining full polarization control over both input and output beams. The protein device is scanned in the x,y plane using large amplitude piezeoelectronic scanners.