Zobrazeno 1 - 10
of 445
pro vyhledávání: '"Ramanathan, C."'
Publikováno v:
Phys. Rev. B 98, 180405 (2018)
We use above-bandgap optical excitation, via a 1047 nm laser, to hyperpolarize the $^{31}$P spins in low-doped (N$_D =6\times10^{15}$ cm$^{-3}$) natural abundance silicon at 4.2 K and 6.7 T, and inductively detect the resulting NMR signal. The $30$ k
Externí odkaz:
http://arxiv.org/abs/1807.08746
Autor:
Ajoy, A., Nazaryan, R., Liu, K., Lv, X., Safvati, B., Wang, G., Druga, E., Reimer, J. A., Suter, D., Ramanathan, C., Meriles, C. A., Pines, A.
Dynamic Nuclear Polarization (DNP) has enabled enormous gains in magnetic resonance signals and led to vastly accelerated NMR/MRI imaging and spectroscopy. Unlike conventional cw-techniques, DNP methods that exploit the full electron spectrum are app
Externí odkaz:
http://arxiv.org/abs/1807.07664
Autor:
Gumann, P., Patange, O., Ramanathan, C., Haas, H., Moussa, O., Thewalt, M. L. W., Riemann, H., Abrosimov, N. V., Becker, P., Pohl, H. -J., Itoh, K. M., Cory, D. G.
Publikováno v:
Phys. Rev. Lett. 113, 267604 (2014)
We experimentally demonstrate the inductive readout of optically hyperpolarized phosphorus-31 donor nuclear spins in an isotopically enriched silicon-28 crystal. The concentration of phosphorus donors in the crystal was 1.5 x 10$^{15}$ cm$^{-3}$, thr
Externí odkaz:
http://arxiv.org/abs/1407.5352
Publikováno v:
Phys. Rev. B 87, 161306(R) (2013)
Direct dynamic nuclear polarization of 1H nuclei in frozen water and water-ethanol mixtures is demonstrated using silicon nanoparticles as the polarizing agent. Electron spins at dangling-bond sites near the silicon surface are identified as the sour
Externí odkaz:
http://arxiv.org/abs/1206.5125
Publikováno v:
Phys. Rev. B 84 035304 (2011)
We investigate the low-field relaxation of nuclear hyperpolarization in undoped and highly doped silicon microparticles at room temperature following removal from high field. For nominally undoped particles, two relaxation time scales are identified
Externí odkaz:
http://arxiv.org/abs/1103.3918
Autor:
Aptekar, J. W., Cassidy, M. C., Johnson, A. C., Barton, R. A., Lee, M. Y., Ogier, A. C., Vo, C., Anahtar, M. N., Ren, Y., Bhatia, S. N., Ramanathan, C., Cory, D. G., Hill, A. L., Mair, R. W., Rosen, M. S., Walsworth, R. L., Marcus, C. M.
Publikováno v:
ACS Nano 3, 4003 (2009)
Silicon nanoparticles are experimentally investigated as a potential hyperpolarized, targetable MRI imaging agent. Nuclear T_1 times at room temperature for a variety of Si nanoparticles are found to be remarkably long (10^2 to 10^4 s) - roughly cons
Externí odkaz:
http://arxiv.org/abs/0902.0269
Publikováno v:
Phys. Rev. Lett. 100, 127601 (2008)
We report record high Si-29 spin polarization obtained using dynamic nuclear polarization in microcrystalline silicon powder. Unpaired electrons in this silicon powder are due to dangling bonds in the amorphous region of this intrinsically heterogene
Externí odkaz:
http://arxiv.org/abs/0711.4076
Autor:
Baugh, J., Chamilliard, J., Chandrashekar, C. M., Ditty, M., Hubbard, A., Laflamme, R., Laforest, M., Maslov, D., Moussa, O., Negrevergne, C., Silva, M., Simmons, S., Ryan, C. A., Cory, D. G., Hodges, J. S., Ramanathan, C.
Publikováno v:
Physics in Canada, Theme Issue - Quantum Computing and Quantum Information, Vol. 63, No. 4, 197-206, Oct.-Dec. 2007
This paper describes recent progress using nuclear magnetic resonance (NMR) as a platform for implementing quantum information processing (QIP) tasks. The basic ideas of NMR QIP are detailed, examining the successes and limitations of liquid and soli
Externí odkaz:
http://arxiv.org/abs/0710.1447
Publikováno v:
Phys. Rev. B 71, 054403 (2005)
We develop a linear response formalism for nuclear spin diffusion in a dipolar coupled solid. The theory applies to the high-temperature, long-wavelength regime studied in the recent experiments of Boutis et al. [Phys. Rev. Lett. 92, 137201 (2004)],
Externí odkaz:
http://arxiv.org/abs/cond-mat/0401013
Publikováno v:
Phys. Rev. Lett., vol 92, article 137201 (2004)
Reciprocal space measurements of spin diffusion in a single crystal of calcium fluoride (CaF$_2$) have been extended to dipolar ordered states. The experimental results for the component of the spin diffusion parallel with the external field are $D_{
Externí odkaz:
http://arxiv.org/abs/cond-mat/0308573