Atom interferometry tests of local Lorentz invariance in gravity and electrodynamics (2009)
Chung, Keng-Yeow, Chiow, Sheng-wey, Herrmann, Sven, Chu, Steven, Mueller, Holger
We present atom-interferometer tests of the local Lorentz invariance of post-Newtonian gravity. An experiment probing for anomalous vertical gravity on Earth, which has already been performed by us,...
Atom interferometers with scalable enclosed area (2009)
Mueller, Holger, Chiow, Sheng-wey, Herrmann, Sven, Chu, Steven
Bloch oscillations (i.e., coherent acceleration of matter waves by an optical lattice) and Bragg diffraction are integrated into light-pulse atom interferometers with large momentum splitting between...
PAST PRECISION MEASUREMENT GRANT HOLDER WINS NOBEL PRIZE (2009)
Is Identified, The Nobel, Prize Physics, Jila Fellows, Carl Wieman Of, ...
the University of Colorado, and Wolfgang Ketterle of MIT for their work on Bose-Einstein condensation of atoms. In 1979, Carl Wieman, then at the University of Michigan, was awarded a NIST Precision...
6 W, 1 kHz linewidth, tunable continuous-wave near-infrared laser (2009)
Chiow, Sheng-wey, Herrmann, Sven, Mueller, Holger, Chu, Steven
A modified Coherent 899-21 titanium sapphire laser is injection locked to produce 6-6.5 W of single-frequency light at 852 nm. After closed-loop amplitude control and frequency stabilization to a...
Noise-Immune Conjugate Large-Area Atom Interferometers (2009)
Herrmann, Sven, Chiow, Sheng-wey, Chu, Steven, Mueller, Holger
We present a pair of simultaneous conjugate Ramsey-Borde atom interferometers (SCI) using large (20\hbar k)-momentum transfer (LMT) beam splitters, where \hbar k is the photon momentum. Simultaneous...
Yu-kwong Kwok, Sai-wing Lei, Steven Chu, Leo Chung, Chun-yi Lee, ...
Pervasive computing environments are useful for efficiently disseminating and generating new information. However, many challenging research problems need to be solved before such a system can be...
Atom Interferometry with up to 24-Photon-Momentum-Transfer Beam Splitters (2007)
Mueller, Holger, Chiow, Sheng-wey, Long, Quan, Herrmann, Sven, Chu, Steven
We present up to 24-photon Bragg diffraction as a beam splitter in light-pulse atom interferometers to achieve the largest splitting in momentum space so far. Relative to the 2-photon processes used...
Atom Interferometry tests of the isotropy of post-Newtonian gravity (2007)
Mueller, Holger, Chiow, Sheng-wey, Herrmann, Sven, Chu, Steven, Chung, Keng-Yeow
We present a test of the local Lorentz invariance of post-Newtonian gravity by monitoring Earth's gravity with a Mach-Zehnder atom interferometer that features a resolution of about...
Nanosecond electro-optical switching with a repetition rate above 20MHz (2007)
Mueller, Holger, Chiow, Sheng-wey, Herrmann, Sven, Chu, Steven
We describe an electro-optical switch based on a commercial electro-optic modulator (modified for high-speed operation) and a 340V pulser having a rise time of 2.2ns (at 250V). It can produce...
Extended cavity diode lasers with tracked resonances (2007)
Chiow, Sheng-wey, Long, Quan, Vo, Christoph, Mueller, Holger, Chu, Steven
We present a painless, almost-free upgrade to present extended cavity diode lasers (ECDLs), which improves the long term mode-hop free performance by stabilizing the resonance of the internal cavity...
One at a time, live tracking of NGF axonal transport using quantum dots (2007)
Cui, Bianxiao, Wu, Chengbiao, Chen, Liang, Ramirez, Alfredo, Bearer, Elaine L., Li, Wei-Ping, ...
Retrograde axonal transport of nerve growth factor (NGF) signals is critical for the survival, differentiation, and maintenance of peripheral sympathetic and sensory neurons and basal forebrain...
Mueller, Holger, Chiow, Sheng-wey, Chu, Steven
We present an analytic theory of the diffraction of (matter) waves by a lattice in the "quasi-Bragg" regime, by which we mean the transition region between the long-interaction Bragg and...
Thiostrepton inhibition of tRNA delivery to the ribosome (2007)
Gonzalez, Ruben L., Chu, Steven, Puglisi, Joseph D.
Ribosome-stimulated hydrolysis of guanosine-5′-triphosphate (GTP) by guanosine triphosphatase (GTPase) translation factors drives protein synthesis by the ribosome. Allosteric coupling of GTP...
A new photon recoil experiment: towards a determination of the fine structure constant (2006)
Mueller, Holger, Chiow, Sheng-wey, Long, Quan, Vo, Christoph, Chu, Steven
We report on progress towards a measurement of the fine structure constant to an accuracy of $5\times 10^{-10}$ or better by measuring the ratio of the Planck constant to the mass of the cesium atom....
Ding, Jianqing, Allen, Elizabeth, Wang, Wei, Valle, Angela, Wu, Chengbiao, Nardine, Timothy, ...
Mutations in gigaxonin were identified in giant axonal neuropathy (GAN), an autosomal recessive disorder. To understand how disruption of gigaxonin's function leads to neurodegeneration, we ablated...
Ding, Jianqing, Allen, Elizabeth, Wang, Wei, Valle, Angela, Wu, Chengbiao, Nardine, Timothy, ...
Mutations in gigaxonin were identified in giant axonal neuropathy (GAN), an autosomal recessive disorder. To understand how disruption of gigaxonin's function leads to neurodegeneration, we ablated...
Mueller, Holger, Chiow, Sheng-wey, Long, Quan, Chu, Steven
We demonstrate phase lock of two >1.6W Titanium:sapphire lasers with a phase noise of -138dBc/Hz at 1MHz from the carrier, using an intra-cavity electro-optic phase modulator. The residual phase...
Active sub-Rayleigh alignment of parallel or antiparallel laser beams (2005)
Mueller, Holger, Chiow, Sheng-wey, Long, Quan, Vo, Christoph, Chu, Steven
We measure and stabilize the relative angle of (anti-)parallel laser beams to 5 nanoradian per root Hertz resolution by comparing the phases of radio frequency beat notes on a quadrant photodetector....
Gemelke, Nathan, Sarajlic, Edina, Bidel, Yannick, Hong, Seokchan, Chu, Steven
We observe the formation of momentum distributions indicative of spatial period-doubling of superfluid Bose-Einstein condensates in periodically translated optical lattices. The effect is attributed...
Site-specific labeling of the ribosome for single-molecule spectroscopy (2005)
Dorywalska, Magdalena, Blanchard, Scott C., Gonzalez, Ruben L., Kim, Harold D., Chu, Steven, Puglisi, Joseph D.
Single-molecule fluorescence spectroscopy can reveal mechanistic and kinetic details that may not be observed in static structural and bulk biochemical studies of protein synthesis. One approach...
Ultracold Cs$_2$ Feshbach Spectroscopy (2003)
Chin, Cheng, Vuletic, Vladan, Kerman, Andrew J., Chu, Steven, Tiesinga, Eite, Leo, Paul J., ...
We have observed and located more than 60 magnetic field-induced Feshbach resonances in ultracold collisions of ground-state $^{133}$Cs atoms. These resonances are associated with molecular states...
Sensitive Detection of Cold Cesium Molecules by Radiative Feshbach Spectroscopy (2002)
Chin, Cheng, Kerman, Andrew J., Vuletić, Vladan, Chu, Steven
We observe the dynamic formation of $Cs_2$ molecules near Feshbach resonances in a cold sample of atomic cesium using an external probe beam. This method is 300 times more sensitive than previous...
Laser Cooling and Trapping of Atoms and Particles. (1998)
The program was to explore the use of light to manipulate atoms And other particles, particularly the cooling and trapping of atoms, the manipulation of biological molecules, and the creations of new...
Atomic Fountain Microwave Clock. (1998)
The grant as in support of a research program to explore the possibility of a microwave atomic clock based on an atomic fountain of cesium atoms. During the two year granting period, the following...
Cooling and Trapping of Atoms and Particles. (1998)
Work in several areas of laser cooling and trapping of atoms were done during the granting period. Work in atom manipulation with Raman pulses of light, atom interferometers, atomic fountain...
Cooling and Trapping of Atoms and Particles (1998)
We showed that it is possible to cool atoms in a one dimensional optical lattice using to a novel degenerate sideband cooling technique. This method was then extended to a three dimension optical...
Applications of Laser Cooling and Trapping (1998)
This grant was used to support graduate students in training. It was used primarily to support a student, Joel Hensley, who was working on an experiment effort to measure the recoil momentum of an...
Cooling and Trapping of Atoms and Particles (1998)
In this work, we report a summary of the more than 60 magnetic field-induced Feshbach resonances in ultracold collisions of ground-state cesium atoms. The detection is based on elastic, inelastic and...
Atom Interferometry and New Cooling Methods (AASERT-92). (1997)
This AASERT grant has provided research and training support for two students, Heun Jin Lee and Doug Smith. Both are U S. citizens. Doug Smith has actively participated in a number of experiments...
Measurement of the positronium 13S1-23S1 interval by continuous-wave two-photon excitation (1993)
Fee, Michale S., Mills, A. P., Chu, Steven, Shaw, E. D., Danzmann, Karsten, Chichester, R. J., ...
Using continuous-wave excitation to eliminate the problems inherent with pulsed laser measurements of nonlinear transitions, we have measured the 13S1-23S1 interval in positronium (Ps) to be 1 233...
Measurement of the positronium 1 3S1–2 3S1 interval by continuous-wave two-photon excitation (1993)
Fee, Michale S., Chu, Steven, Mills, A. P., Chichester, R. J., Zuckerman, D. M., Shaw, E. D., ...
Positronium is the quasistable bound system consisting of an electron and its antiparticle, the positron. Its energy levels can be explained to a high degree of accuracy by the electromagnetic...
Optical heterodyne measurement of pulsed lasers: Toward high-precision pulsed spectroscopy (1992)
Fee, Michale S., Danzmann, Karsten, Chu, Steven
In this paper we explore theoretically and experimentally the effect of fluctuations in the instantaneous frequency of a pulsed laser on the shape and position of two-photon transition spectra. The...
Fee, Michale S., Mills, A. P., Shaw, E. D., Chichester, R. J., Zuckerman, D. M., Chu, Steven, ...
Using a spatially filtered pulsed laser at 486 nm we have photoexcited positronium to the 2S state and detected it via a delayed and spatially separated 532-nm photoionization pulse. We have extended...
Danzmann, Karsten, Fee, Michale S., Chu, Steven
A scheme for a precision measurement of the 1S-2S transition frequency in positronium and muonium is reported, and corrections to the two most recent experiments are presented which bring their...
Observation of the forbidden magnetic dipole transition 6²P1/2 - 7² P1/2 in atomic thallium. (1976)
"LBL-5731."
Ligand-induced conformational changes observed in single RNA molecules
Ha, Taekjip, Zhuang, Xiaowei, Kim, Harold D., Orr, Jeffrey W., Williamson, James R., Chu, Steven
We present the first demonstration that fluorescence resonance energy transfer can be used to track the motion of a single molecule undergoing conformational changes. As a model system, the...
Fluorescence quenching: A tool for single-molecule protein-folding study
Zhuang, Xiaowei, Ha, Taekjip, Kim, Harold D., Centner, Thomas, Labeit, Siegfried, Chu, Steven
By using titin as a model system, we have demonstrated that fluorescence quenching can be used to study protein folding at the single molecule level. The unfolded titin molecules with multiple dye...
Exploring the folding landscape of a structured RNA
Russell, Rick, Zhuang, Xiaowei, Babcock, Hazen P., Millett, Ian S., Doniach, Sebastian, Chu, Steven, ...
Structured RNAs achieve their active states by traversing complex, multidimensional energetic landscapes. Here we probe the folding landscape of the Tetrahymena ribozyme by using a powerful approach:...
Kim, Harold D., Nienhaus, G. Ulrich, Ha, Taekjip, Orr, Jeffrey W., Williamson, James R., Chu, Steven
Fluorescence correlation spectroscopy (FCS) of fluorescence resonant energy transfer (FRET) on immobilized individual fluorophores was used to study the Mg2+-facilitated conformational change of an...
Single-molecule studies of SNARE complex assembly reveal parallel and antiparallel configurations
Weninger, Keith, Bowen, Mark E., Chu, Steven, Brunger, Axel T.
Vesicle fusion in eukaryotes is thought to involve the assembly of a highly conserved family of proteins termed soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) into a...
tRNA dynamics on the ribosome during translation
Blanchard, Scott C., Kim, Harold D., Gonzalez, Ruben L., Puglisi, Joseph D., Chu, Steven
Using single-molecule fluorescence spectroscopy, time-resolved conformational changes between fluorescently labeled tRNA have been characterized within surface-immobilized ribosomes proceeding...
Site-specific labeling of the ribosome for single-molecule spectroscopy
Dorywalska, Magdalena, Blanchard, Scott C., Gonzalez, Ruben L., Kim, Harold D., Chu, Steven, Puglisi, Joseph D.
Single-molecule fluorescence spectroscopy can reveal mechanistic and kinetic details that may not be observed in static structural and bulk biochemical studies of protein synthesis. One approach...
Bowen, Mark E., Weninger, Keith, Brunger, Axel T., Chu, Steven
A single molecule fluorescence assay is presented for studying the mechanism of soluble N-ethyl maleimide sensitive-factor attachment protein receptors (SNAREs)-mediated liposome fusion to supported...
Single-Molecule Studies of Synaptotagmin and Complexin Binding to the SNARE Complex
Bowen, Mark E., Weninger, Keith, Ernst, James, Chu, Steven, Brunger, Axel T.
The assembly of multiprotein complexes at the membrane interface governs many signaling processes in cells. However, very few methods exist for obtaining biophysical information about protein complex...
Ligand-induced conformational changes observed in single RNA molecules
Ha, Taekjip, Zhuang, Xiaowei, Kim, Harold D., Orr, Jeffrey W., Williamson, James R., Chu, Steven
We present the first demonstration that fluorescence resonance energy transfer can be used to track the motion of a single molecule undergoing conformational changes. As a model system, the...
Fluorescence quenching: A tool for single-molecule protein-folding study
Zhuang, Xiaowei, Ha, Taekjip, Kim, Harold D., Centner, Thomas, Labeit, Siegfried, Chu, Steven
By using titin as a model system, we have demonstrated that fluorescence quenching can be used to study protein folding at the single molecule level. The unfolded titin molecules with multiple dye...
Exploring the folding landscape of a structured RNA
Russell, Rick, Zhuang, Xiaowei, Babcock, Hazen P., Millett, Ian S., Doniach, Sebastian, Chu, Steven, ...
Structured RNAs achieve their active states by traversing complex, multidimensional energetic landscapes. Here we probe the folding landscape of the Tetrahymena ribozyme by using a powerful approach:...
Kim, Harold D., Nienhaus, G. Ulrich, Ha, Taekjip, Orr, Jeffrey W., Williamson, James R., Chu, Steven
Fluorescence correlation spectroscopy (FCS) of fluorescence resonant energy transfer (FRET) on immobilized individual fluorophores was used to study the Mg2+-facilitated conformational change of an...
Single-molecule studies of SNARE complex assembly reveal parallel and antiparallel configurations
Weninger, Keith, Bowen, Mark E., Chu, Steven, Brunger, Axel T.
Vesicle fusion in eukaryotes is thought to involve the assembly of a highly conserved family of proteins termed soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) into a...
tRNA dynamics on the ribosome during translation
Blanchard, Scott C., Kim, Harold D., Gonzalez, Ruben L., Puglisi, Joseph D., Chu, Steven
Using single-molecule fluorescence spectroscopy, time-resolved conformational changes between fluorescently labeled tRNA have been characterized within surface-immobilized ribosomes proceeding...
Site-specific labeling of the ribosome for single-molecule spectroscopy
Dorywalska, Magdalena, Blanchard, Scott C., Gonzalez, Ruben L., Kim, Harold D., Chu, Steven, Puglisi, Joseph D.
Single-molecule fluorescence spectroscopy can reveal mechanistic and kinetic details that may not be observed in static structural and bulk biochemical studies of protein synthesis. One approach...
Bowen, Mark E., Weninger, Keith, Brunger, Axel T., Chu, Steven
A single molecule fluorescence assay is presented for studying the mechanism of soluble N-ethyl maleimide sensitive-factor attachment protein receptors (SNAREs)-mediated liposome fusion to supported...
Single-Molecule Studies of Synaptotagmin and Complexin Binding to the SNARE Complex
Bowen, Mark E., Weninger, Keith, Ernst, James, Chu, Steven, Brunger, Axel T.
The assembly of multiprotein complexes at the membrane interface governs many signaling processes in cells. However, very few methods exist for obtaining biophysical information about protein complex...
One at a time, live tracking of NGF axonal transport using quantum dots
Cui, Bianxiao, Wu, Chengbiao, Chen, Liang, Ramirez, Alfredo, Bearer, Elaine L., Li, Wei-Ping, ...
Retrograde axonal transport of nerve growth factor (NGF) signals is critical for the survival, differentiation, and maintenance of peripheral sympathetic and sensory neurons and basal forebrain...
The role of fluctuations in tRNA selection by the ribosome
Lee, Tae-Hee, Blanchard, Scott C., Kim, Harold D., Puglisi, Joseph D., Chu, Steven
The detailed mechanism of how the ribosome decodes protein sequence information with an abnormally high accuracy, after 40 years of study, remains elusive. A critical element in selecting correct...
Measuring the Folding Transition Time of Single RNA Molecules
Lee, Tae-Hee, Lapidus, Lisa J., Zhao, Wei, Travers, Kevin J., Herschlag, Daniel, Chu, Steven
We describe a new, time-apertured photon correlation method for resolving the transition time between two states of RNA in folding—i.e., the time of the transition between states rather than the...
Thiostrepton inhibition of tRNA delivery to the ribosome
Gonzalez, Ruben L., Chu, Steven, Puglisi, Joseph D.
Ribosome-stimulated hydrolysis of guanosine-5′-triphosphate (GTP) by guanosine triphosphatase (GTPase) translation factors drives protein synthesis by the ribosome. Allosteric coupling of GTP...
Fluctuations of Transfer RNAs between Classical and Hybrid States
Kim, Harold D., Puglisi, Joseph D., Chu, Steven
Adjacent transfer RNAs (tRNAs) in the A- and P-sites of the ribosome are in dynamic equilibrium between two different conformations called classical and hybrid states before translocation. Here, we...
Resolving cadherin interactions and binding cooperativity at the single-molecule level
Zhang, Yunxiang, Sivasankar, Sanjeevi, Nelson, W. James, Chu, Steven
The cadherin family of Ca2+-dependent cell adhesion proteins are critical for the morphogenesis and functional organization of tissues in multicellular organisms, but the molecular interactions...