A5046979085- Mechanical and Optical Resonators
- Photonic and Optical Devices
- Quantum Information and Cryptography
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced MEMS and NEMS Technologies
- Force Microscopy Techniques and Applications
- Quantum optics and atomic interactions
- Advanced Fiber Laser Technologies
- Advanced Fiber Optic Sensors
- Advanced Thermodynamics and Statistical Mechanics
- Atomic and Subatomic Physics Research
- Quantum Mechanics and Applications
- Geophysics and Sensor Technology
- Advanced Frequency and Time Standards
- Scientific Measurement and Uncertainty Evaluation
- Experimental and Theoretical Physics Studies
- Acoustic Wave Resonator Technologies
- Advanced Electrical Measurement Techniques
- Photoacoustic and Ultrasonic Imaging
- Photonic Crystals and Applications
- Random lasers and scattering media
- Solar and Space Plasma Dynamics
- Analytical Chemistry and Sensors
- Acoustic Wave Phenomena Research
- Quantum Electrodynamics and Casimir Effect
University of Pittsburgh
2019-2023
Pittsburgh Quantum Institute
2020-2023
National Institute of Standards and Technology
2012-2020
Joint Quantum Institute
2016-2017
Physical Measurement Laboratory
2015-2017
University of Maryland, College Park
2017
Material Measurement Laboratory
2015-2017
University of Colorado Boulder
2011-2016
Joint Institute for Laboratory Astrophysics
2011-2016
University of California, Berkeley
2004-2012
The quantum mechanics of position measurement a macroscopic object is typically inaccessible because strong coupling to the environment and classical noise. In this work, we monitor mechanical resonator subject an increasingly continuous observe back-action force that rises in accordance with Heisenberg uncertainty limit. For our optically based measurements, takes form fluctuating radiation pressure from Poisson-distributed photons coherent field, termed shot We demonstrate comparable...
We create squeezed light by exploiting the quantum nature of mechanical interaction between laser and a membrane resonator embedded in an optical cavity. The radiation-pressure shot noise (fluctuating force from amplitude noise) induces motion well above that thermally driven motion. This imprints phase shift on light, hence correlating noise, consequence which is squeezing. experimentally demonstrate strong continuous optomechanical squeezing 1.7±0.2 dB below shot-noise level. peak level...
The radiation pressure of light can act to damp and cool the vibrational motion a mechanical resonator, but even if field has no thermal component, shot noise still sets limit on minimum phonon occupation. In optomechanical sideband cooling in cavity, finite off-resonant Stokes scattering defined by cavity linewidth combined with fluctuations dictates quantum backaction limit, analogous Doppler atomic laser cooling. our work, we micromechanical membrane resonator limit. Monitoring optical...
We have produced Bose-Einstein condensates in a ring-shaped magnetic waveguide. The few-millimeter diameter, nonzero-bias ring is formed from time-averaged quadrupole ring. Condensates that propagate around the make several revolutions within time it takes for them to expand fill shape ideally suited studies of vorticity multiply connected geometry and promising as rotation sensor.
We present an atom-chip-based realization of quantum cavity optomechanics with cold atoms localized within a Fabry-Perot cavity. Effective sub-wavelength positioning the atomic ensemble allows for tuning linear and quadratic optomechanical coupling parameters, varying sensitivity to displacement strain compressible gaseous cantilever. observe effects such on optical nonlinearity frequency shifts, providing their first characterization in quadratic-coupling regime.
We study the mechanical quality factors of bilayer aluminum--silicon-nitride membranes. By coating ultrahigh-$Q$ ${\mathrm{Si}}_{3}{\mathrm{N}}_{4}$ membranes with a more lossy metal, we can precisely measure effect material loss on $Q$'s tensioned resonator modes over large range frequencies. develop theoretical model that interprets our results and predicts damping be reduced significantly by patterning metal film. Using such patterning, fabricate Al-${\mathrm{Si}}_{3}{\mathrm{N}}_{4}$...
The act of position measurement alters the motion an object being measured. This quantum backaction is typically much smaller than thermal a room-temperature and thus difficult to observe. By shining laser light through nanomechanical beam, we measure beam's thermally driven vibrations perturb its with optical force fluctuations at level dictated by Heisenberg measurement-disturbance uncertainty relation. We demonstrate cross-correlation technique distinguish optically from motion, observing...
Numerous astrophysical and cosmological observations are best explained by the existence of dark matter, a mass density which interacts only very weakly with visible, baryonic matter. Searching for extremely weak signals produced this matter strongly motivate development new, ultra-sensitive detector technologies. Paradigmatic advances in control readout massive mechanical systems, both classical quantum regimes, have enabled unprecedented levels sensitivity. In white paper, we outline...
The temperature dependence of the asymmetry between Stokes and anti-Stokes Raman scattering can be exploited for self-calibrating, optically based thermometry. In context cavity optomechanics, we observe cavity-enhanced light interacting with standing-wave drumhead modes a ${\mathrm{Si}}_{3}{\mathrm{N}}_{4}$ membrane mechanical resonator. ratio amplitude to scattered is used measure temperatures cooled modes, down level few vibrational quanta. We demonstrate that Raman-ratio technique allows...
We demonstrate efficient mechanically-mediated transduction between microwave and optical signals using a micromechanical SiN membrane. This interface has the potential to transform information these vastly different frequencies while maintaining fragile quantum state.
The quantum coupling of individual superconducting qubits to microwave photons leads remarkable experimental opportunities. Here we consider the phononic case where qubit is coupled an electromagnetic surface acoustic wave antenna that enables supersonic (electromagnetic) propagation oscillations. This can be considered as a giant atom many phonon wavelengths long. We study exactly solvable toy model captures these effects, and find this non-Markovian has suppressed relaxation, so long...
We describe a cryogenic cavity-optomechanical system that combines Si3N4 membranes with mechanically rigid Fabry–Perot cavity. The extremely high products of quality factor and frequency the allow us to cool MHz mechanical mode phonon occupation , starting at bath temperature 5 K. show even cold temperatures thermally occupied modes cavity elements can be limitation, we discuss methods reduce these effects sufficiently for achieving ground state cooling. This promising new platform should...
A phononic crystal can control the acoustic coupling between a resonator and its support structure. We micromachine bandgap shield for high Q silicon nitride membranes study driven displacement spectra of their structures. find that inside observed bandgaps, density amplitude non-membrane modes are greatly suppressed, membrane shielded from an external mechanical drive by up to 30 dB.
The measurement science in realizing and disseminating the unit for pressure International System of Units, pascal (Pa), has been subject much interest at National Institute Standards Technology (NIST). Modern optical-based techniques metrology have investigated, including multiphoton ionization cavity ringdown spectroscopy. Work is ongoing to recast terms quantum properties fundamental constants doing so make vacuum consistent with global trend toward quantum-based metrology. NIST projects...
Optomechanical systems show tremendous promise for the high-sensitivity sensing of forces and modification mechanical properties via light. For example, similar to neutral atoms trapped ions, laser cooling motion by radiation pressure can take single modes their ground state. Conventional optomechanical is able introduce an additional damping channel while keeping its thermal noise at same level, and, as a consequence, effective temperature mode lowered. However, ratio quality factor remains...
We investigate the optomechanical properties of tensile-strained ternary InxGa1−xP nanomembranes grown on GaAs. This material system combines benefits highly strained membranes, similar to those based stoichiometric silicon nitride, with unique thin-film semiconductor single crystals, as previously demonstrated suspended Here, we employ lattice mismatch in epitaxial growth impart an intrinsic tensile strain a monocrystalline thin film (approximately 30 nm thick). These structures exhibit...
Nanomechanical systems are generally embedded in a macroscopic environment where the sources of thermal noise difficult to pinpoint. We engineer silicon nitride membrane optomechanical resonator such that its is acoustically driven by spatially well-defined remote bath. This bath acts as an acoustic blackbody emitting and absorbing radiation through substrate. Our system sensitive detector for temperature photoacoustic imaging. demonstrate nanomechanical mode governed not local material...
We have developed an improved scheme for loading atoms into a magneto-optical trap (MOT) from directed alkali metal dispenser in < 10^-10 torr ultra-high vacuum conditions. A current-driven was surrounded with cold absorbing "shroud" held at 0 C, pumping rubidium not the MOT. This nearly eliminates background and reduces detrimental rise pressure normally associated these devices. The system can be well-described as current-controlled, rapidly-switched, two-temperature thermal beam, used to...
By shining laser light through a nanomechanical beam, we measure the beam's thermally driven vibrations and perturb its motion with optical forces at level dictated by Heisenberg measurement-disturbance uncertainty relation. Such quantum backaction is typically difficult to observe room temperature where intensity fluctuations many orders of magnitude smaller than thermal motion. We demonstrate cross-correlation technique distinguish optically from motion, observing this signature up...