Singlet-Triplet Physics and Shell Filling in Carbon Nanotube Double Quantum Dots
arXiv:0711.3245 · doi:10.1038/nphys987
Abstract
An artifcial two-atomic molecule, also called a double quantum dot (DQD), is an ideal system for exploring few electron physics. Spin-entanglement between just two electrons can be explored in such systems where singlet and triplet states are accessible. These two spin-states can be regarded as the two states in a quantum two-state system, a so-called singlet-triplet qubit. A very attractive material for realizing spin based qubits is the carbon nanotube (CNT), because it is expected to have a very long spin coherence time. Here we show the existence of a gate-tunable singlet-triplet qubit in a CNT DQD. We show that the CNT DQD has clear shell structures of both four and eight electrons, with the singlet-triplet qubit present in the four-electron shells. We furthermore observe inelastic cotunneling via the singlet and triplet states, which we use to probe the splitting between singlet and triplet, in good agreement with theory.
Supplement available at: http://www.fys.ku.dk/~hij/public/singlet-triple_supp.pdf
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- Carbon nanotubes for coherent spintronic devices
- Supercurrent in a double quantum dot
- Graphene quantum dots for valley-based quantum computing: A feasibility study
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- Nuclear spin dynamics and Zeno effect in quantum dots and defect centers
- Two-Impurity Yu-Shiba-Rusinov States in Coupled Quantum Dots
- Ground-state cooling the vibrations of suspended carbon-nanotubes with constant electron current
- Two-channel Kondo physics in tunnel-coupled double quantum dots
- Josephson junctions in double nanowires bridged by in-situ deposited superconductors
- A Schottky top-gated two-dimensional electron system in a nuclear spin free Si/SiGe heterostructure
- Transport in coupled graphene-nanotube quantum devices
- Spin and Orbital Splitting in Ferromagnetic Contacted Single Wall Carbon Nanotube Devices
- g-Tensor Control in Bent Carbon Nanotube Quantum Dots
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