English
Related papers

Related papers: Electron Spin Relaxation in Graphene Nanoribbon Qu…

200 papers

Spin-ordered electronic states in hydrogen-terminated zigzag nanographene give rise to magnetic quantum phenomena that have sparked renewed interest in carbon-based spintronics. Zigzag graphene nanoribbons (ZGNRs), quasi one-dimensional…

By using analytical solution of a tight-binding model for armchair nanoribbons, it is confirmed that the solution represents the standing wave formed by intervalley scattering and that pseudospin is invariant under the scattering. The phase…

Mesoscale and Nanoscale Physics · Physics 2011-04-14 K. Sasaki , K. Wakabayashi , T. Enoki

Strong magnetic field gradients can produce a synthetic spin-orbit interaction that allows for high fidelity electrical control of single electron spins. We investigate how a field gradient impacts the spin relaxation time T_1 by measuring…

Mesoscale and Nanoscale Physics · Physics 2019-04-23 F. Borjans , D. M. Zajac , T. M. Hazard , J. R. Petta

We propose how to form spin qubits in graphene. A crucial requirement to achieve this goal is to find quantum dot states where the usual valley degeneracy in bulk graphene is lifted. We show that this problem can be avoided in quantum dots…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 B. Trauzettel , Denis V. Bulaev , Daniel Loss , Guido Burkard

Graphene nanoribbons (GNRs) are a family of one-dimensional (1D) materials carved from graphene lattice. GNRs possess high mobility and current carrying capability, sizable bandgap, and versatile electronic properties tailored by the…

Mesoscale and Nanoscale Physics · Physics 2021-10-08 Haomin Wang , Hui Shan Wang , Chuanxu Ma , Lingxiu Chen , Chengxin Jiang , Chen Chen , Xiaoming Xie , An-Ping Li , Xinran Wang

We theoretically investigate the spin-charge transport in two-terminal device of graphene nanoribbons in the presence of an uniform uniaxial strain, spin-orbit coupling, exchange field and smooth staggered potential. We show that the…

Mesoscale and Nanoscale Physics · Physics 2014-09-25 Ginetom S. Diniz , Marcos R. Guassi , Fanyao Qu

We study spin relaxation and decoherence in a GaAs quantum dot due to spin-orbit interaction. We derive an effective Hamiltonian which couples the electron spin to phonons or any other fluctuation of the dot potential. We show that the spin…

Mesoscale and Nanoscale Physics · Physics 2016-08-31 Vitaly N. Golovach , Alexander Khaetskii , Daniel Loss

In this review we discuss the multifaceted problem of spin transport in hydrogenated graphene from a theoretical perspective. The current experimental findings suggest that hydrogenation can either increase or decrease spin lifetimes, which…

We present a microscopic theory for interacting graphene armchair nanoribbon quantum dots. Long range interaction processes are responsible for Coulomb blockade and spin-charge separation. Short range ones, arising from the underlying…

Mesoscale and Nanoscale Physics · Physics 2010-03-23 Sonja Koller , Leonhard Mayrhofer , Milena Grifoni

We investigate spin relaxation in rippled graphene where curvature induces a Zeeman-like spin-orbit coupling with opposite effective magnetic fields along the graphene plane in ${\bf K}$ and ${\bf K}^\prime$ valleys. The joint effect of…

Mesoscale and Nanoscale Physics · Physics 2012-10-10 P. Zhang , Y. Zhou , M. W. Wu

Tailor-made graphene nanostructures can exhibit symmetry-protected topological boundary states that host localized spin-$1/2$ moments. However, one frequently observes charge transfer on coinage metal substrates, which results in spinless…

Zigzag edges of neutral armchair-oriented Graphene Nano-Ribbons show states strongly localized at those edges. They behave as free radicals that can capture electrons during processing, increasing ribbon's stability. Thus, charging and its…

Mesoscale and Nanoscale Physics · Physics 2019-07-26 E. Louis , E. San-Fabian , G. Chiappe , J. A. Verges

We experimentally study the electronic spin transport in hBN encapsulated single layer graphene nonlocal spin valves. The use of top and bottom gates allows us to control the carrier density and the electric field independently. The spin…

Mesoscale and Nanoscale Physics · Physics 2014-08-27 M. H. D. Guimarães , P. J. Zomer , J. Ingla-Aynés , J. C. Brant , N. Tombros , B. J. van Wees

It is proposed that the observed small (100 ps) spin relaxation time in graphene is due to resonant scattering by local magnetic moments. At resonances, magnetic moments behave as spin hot spots: the spin-flip scattering rates are as large…

Mesoscale and Nanoscale Physics · Physics 2014-03-26 Denis Kochan , Martin Gmitra , Jaroslav Fabian

A theory of electron spin relaxation in semiconducting carbon nanotubes is developed based on the hyperfine interaction with disordered nuclei spins I=1/2 of $^{13}$C isotopes. It is shown that strong radial confinement of electrons…

Materials Science · Physics 2009-11-11 Y. G. Semenov , K. W. Kim , G. J. Iafrate

We show spin lifetimes of 12.6 ns and spin diffusion lengths as long as 30.5 \mu m in single layer graphene non-local spin transport devices at room temperature. This is accomplished by the fabrication of Co/MgO-electrodes on a Si/SiO$_2$…

Since graphene nanoribbons are thin and flimsy, they need support. Support gives firm ground for applications, and adhesion holds ribbons flat, although not necessarily straight: ribbons with high aspect ratio are prone to bend. The effects…

Mesoscale and Nanoscale Physics · Physics 2012-05-18 Pekka Koskinen

Graphene-based nanostructures exhibit a vast range of exciting electronic properties that are absent in extended graphene. For example, quantum confinement in carbon nanotubes and armchair graphene nanoribbons (AGNRs) leads to the opening…

Hole spins in semiconductors are a potential qubit alternative to electron spins. In nuclear-spin-rich host crystals like GaAs, the hyperfine interaction of hole spins with nuclei is considerably weaker than that for electrons, leading to…

Graphene quantum dots are attractive candidates for solid-state quantum bits. In fact, the predicted weak spin-orbit and hyperfine interaction promise spin qubits with long coherence times. Graphene quantum dot devices have been extensively…