4,683 research outputs found
Topological Defects Coupling Smectic Modulations to Intra-unit-cell Nematicity in Cuprate
We study the coexisting smectic modulations and intra-unit-cell nematicity in
the pseudogap states of underdoped Bi2Sr2CaCu2O8+{\delta}. By visualizing their
spatial components separately, we identified 2\pi topological defects
throughout the phase-fluctuating smectic states. Imaging the locations of large
numbers of these topological defects simultaneously with the fluctuations in
the intra-unit-cell nematicity revealed strong empirical evidence for a
coupling between them. From these observations, we propose a Ginzburg-Landau
functional describing this coupling and demonstrate how it can explain the
coexistence of the smectic and intra-unit-cell broken symmetries and also
correctly predict their interplay at the atomic scale. This theoretical
perspective can lead to unraveling the complexities of the phase diagram of
cuprate high-critical-temperature superconductors
Commensurate period Charge Density Modulations throughout the Pseudogap Regime
Theories based upon strong real space (r-space) electron electron
interactions have long predicted that unidirectional charge density modulations
(CDM) with four unit cell (4) periodicity should occur in the hole doped
cuprate Mott insulator (MI). Experimentally, however, increasing the hole
density p is reported to cause the conventionally defined wavevector of
the CDM to evolve continuously as if driven primarily by momentum space
(k-space) effects. Here we introduce phase resolved electronic structure
visualization for determination of the cuprate CDM wavevector. Remarkably, this
new technique reveals a virtually doping independent locking of the local CDM
wavevector at throughout the underdoped phase diagram of the
canonical cuprate . These observations have significant
fundamental consequences because they are orthogonal to a k-space (Fermi
surface) based picture of the cuprate CDM but are consistent with strong
coupling r-space based theories. Our findings imply that it is the latter that
provide the intrinsic organizational principle for the cuprate CDM state
The JCMT Transient Survey: An Extraordinary Submillimetre Flare in the T Tauri Binary System JW 566
The binary T Tauri system JW 566 in the Orion Molecular Cloud underwent an
energetic, short-lived flare observed at submillimetre wavelengths by the
SCUBA-2 instrument on 26 November 2016 (UT). The emission faded by nearly 50%
during the 31 minute integration. The simultaneous source fluxes averaged over
the observation are 500 +/- 107 mJy/beam at 450 microns and 466 +/- 47 mJy/beam
at 850 microns. The 850 micron flux corresponds to a radio luminosity of
erg/s/Hz, approximately one order of magnitude
brighter (in terms of ) than that of a flare of the young star
GMR-A, detected in Orion in 2003 at 3mm. The event may be the most luminous
known flare associated with a young stellar object and is also the first
coronal flare discovered at sub-mm wavelengths. The spectral index between 450
microns and 850 microns of is broadly consistent with
non-thermal emission. The brightness temperature was in excess of
K. We interpret this event to be a magnetic reconnection that
energised charged particles to emit gyrosynchrotron/synchrotron radiation.Comment: Accepted in ApJ. 16 pages (single column), 6 figure
Feeding a Brown Midrib Corn Silage-Based Diet to Growing Beef Steers Improves Growth Performance and Economic Returns
A feedlot experiment was performed to determine growth performance, ruminal fermentation characteristics, and economic returns for growing beef steers when fed a brown midrib corn silage-based total mixed ration (BMRT) compared with a conventional corn silage-based total mixed ration (CCST). Twenty-four Angus crossbred steers (initial body weight=258±23.2 kg) in individual pens were used in a completely randomized design (n=12). Intake of dry matter was not different between the treatments. Steers fed the BMRT tended to have greater average daily gain (1.54 vs. 1.42 kg d−1; P=0.09) and gain-to-feed ratio (0.165 vs. 0.146; P=0.07) compared with those fed the CCST. Feeding the BMRT increased total volatile fatty acid (VFA) concentration (P=0.01) compared with the CCST, while it decreased molar proportion of acetate (P\u3c0.01), and increased propionate proportion (P=0.01), resulting in decreased acetate-to-propionate ratio compared with the CCST (P\u3c0.01). Steers fed the BMRT increased feed margin (P=0.05) and net return (P=0.02) compared with those fed the CCST throughout the trial. Overall results of this study indicate that feeding the BMRT to growing beef steers enhanced ruminal fermentation and beneficially shifted VFA profiles, which contributed to improved growth and economic performance of steers © 2015, Agricultural Institute of Canada. All Rights Reserved
The JCMT Transient Survey: An Extraordinary Submillimeter Flare in the T Tauri Binary System JW 566
© 2019 The American Astronomical Society. All rights reserved.The binary T Tauri system JW 566 in the Orion Molecular Cloud underwent an energetic, short-lived flare observed at submillimetre wavelengths by the SCUBA-2 instrument on 26 November 2016 (UT). The emission faded by nearly 50% during the 31 minute integration. The simultaneous source fluxes averaged over the observation are 500 +/- 107 mJy/beam at 450 microns and 466 +/- 47 mJy/beam at 850 microns. The 850 micron flux corresponds to a radio luminosity of erg/s/Hz, approximately one order of magnitude brighter (in terms of ) than that of a flare of the young star GMR-A, detected in Orion in 2003 at 3mm. The event may be the most luminous known flare associated with a young stellar object and is also the first coronal flare discovered at sub-mm wavelengths. The spectral index between 450 microns and 850 microns of is broadly consistent with non-thermal emission. The brightness temperature was in excess of K. We interpret this event to be a magnetic reconnection that energised charged particles to emit gyrosynchrotron/synchrotron radiation.Peer reviewedFinal Published versio
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Recruiting, Training, and Engaging Virtual Faculty via an Award-Winning Online Pedagogy Institute -- #NSWM30
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