Resistively detected nuclear magnetic resonance via a single InSb two-dimensional electron gas at high temperature

We report on the demonstration of the resistively detected nuclear magnetic resonance (RDNMR) of a single InSb two-dimensional electron gas (2DEG) at elevated temperatures up to 4 K. The RDNMR signal of 115In in the simplest pseudospin quantum Hall ferromagnet triggered by a large direct current shows a peak-dip line shape, where the nuclear relaxation time T1 at the peak and the dip is different but almost temperature independent. The large Zeeman, cyclotron, and exchange energy scales of the InSb 2DEG contribute to the persistence of the RDNMR signal at high temperatures.Comment: 11pages,3figure

Reactive-site mutants of N-TIMP-3 that selectively inhibit ADAMTS-4 and ADAMTS-5: biological and structural implications.

Published versio

Resistively-detected NMR lineshapes in a quasi-one dimensional electron system

We observe variation in the resistively-detected nuclear magnetic resonance (RDNMR) lineshapes in quantum Hall breakdown. The breakdown is locally occurred in a gate-defined quantum point contact (QPC) region. Of particular interest is the observation of a dispersive lineshape occured when the bulk 2D electron gas (2DEG) is set to $\nu_{\rm{b}} = 2$ and the QPC filling factor to the vicinity of $\nu_{\rm{QPC}} = 1$, strikingly resemble the dispersive lineshape observed on a 2D quantum Hall state. This previously unobserved lineshape in a QPC points to simultaneous occurrence of two hyperfine-mediated spin flip-flop processes within the QPC. Those events give rise to two different sets of nuclei polarized in the opposite direction and positioned at a separate region with different degree of electronic polarizations.Comment: Accepted as a rapid communication in PR

Resolving the Fe xxv Triplet with Chandra in Cen X-3

We present the results of a 45 ks Chandra observation of the high-mass X-ray binary Cen X--3 at orbital phases between 0.13 and 0.40 (in the eclipse post-egress phases). Here we concentrate on the study of discrete features in the energy spectrum at energies between 6 and 7 keV, i.e. on the iron K$_\alpha$ line region, using the High Energy Transmission Grating Spectrometer on board the Chandra satellite. We clearly see a K$_\alpha$ neutral iron line at $\sim 6.40$ keV and were able to distinguish the three lines of the \ion{Fe}{25} triplet at 6.61 keV, 6.67 keV, and 6.72 keV, with an equivalent width of 6 eV, 9 eV, and 5 eV, respectively. The equivalent width of the K$_\alpha$ neutral iron line is 13 eV, an order of magnitude lower than previous measures. We discuss the possibility that the small equivalent width is due to a decrease of the solid angle subtended by the reflector.Comment: 11 pages, 2 figures, To appear in the Astrophysical Journal Letter