Home > News > Coupling of spin and orbital motion of electrons in carbon nanotubes
March 27th, 2008
Coupling of spin and orbital motion of electrons in carbon nanotubes
Abstract:
Electrons in atoms possess both spin and orbital degrees of freedom. In non-relativistic quantum mechanics, these are independent, resulting in large degeneracies in atomic spectra. However, relativistic effects couple the spin and orbital motion, leading to the well-known fine structure in their spectra. The electronic states in defect-free carbon nanotubes are widely believed to be four-fold degenerate1, 2, 3, 4, 5, 6, 7, 8, 9, 10, owing to independent spin and orbital symmetries, and also to possess electron-hole symmetry11. Here we report measurements demonstrating that in clean nanotubes the spin and orbital motion of electrons are coupled, thereby breaking all of these symmetries. This spin-orbit coupling is directly observed as a splitting of the four-fold degeneracy of a single electron in ultra-clean quantum dots. The coupling favours parallel alignment of the orbital and spin magnetic moments for electrons and antiparallel alignment for holes. Our measurements are consistent with recent theories12, 13 that predict the existence of spin-orbit coupling in curved graphene and describe it as a spin-dependent topological phase in nanotubes. Our findings have important implications for spin-based applications in carbon-based systems, entailing new design principles for the realization of quantum bits (qubits) in nanotubes and providing a mechanism for all-electrical control of spins14 in nanotubes.
Source:
nature.com
Bookmark:
| Related News Press |
News and information
Researchers develop molecular qubits that communicate at telecom frequencies October 3rd, 2025
Next-generation quantum communication October 3rd, 2025
"Nanoreactor" cage uses visible light for catalytic and ultra-selective cross-cycloadditions October 3rd, 2025
Spintronics
Quantum materials: Electron spin measured for the first time June 9th, 2023
Quantum Computing
Researchers develop molecular qubits that communicate at telecom frequencies October 3rd, 2025
Researchers tackle the memory bottleneck stalling quantum computing October 3rd, 2025
Japan launches fully domestically produced quantum computer: Expo visitors to experience quantum computing firsthand August 8th, 2025
Discoveries
Researchers develop molecular qubits that communicate at telecom frequencies October 3rd, 2025
Next-generation quantum communication October 3rd, 2025
"Nanoreactor" cage uses visible light for catalytic and ultra-selective cross-cycloadditions October 3rd, 2025
Announcements
Rice membrane extracts lithium from brines with greater speed, less waste October 3rd, 2025
Researchers develop molecular qubits that communicate at telecom frequencies October 3rd, 2025
Next-generation quantum communication October 3rd, 2025
"Nanoreactor" cage uses visible light for catalytic and ultra-selective cross-cycloadditions October 3rd, 2025
Quantum nanoscience
ICFO researchers overcome long-standing bottleneck in single photon detection with twisted 2D materials August 8th, 2025
Programmable electron-induced color router array May 14th, 2025
 |
||
 |
||
| The latest news from around the world, FREE | ||
 |
||
|
|
||
| Premium Products | ||
 |
||
|
Only the news you want to read!
Learn More |
||
 |
||
|
Full-service, expert consulting
Learn More |
||
|
|
||