Putting spin into carbon nanoelectronics
Lead Research Organisation:
University of Oxford
Department Name: Materials
Abstract
Single walled carbon nanotubes are proving themselves to be remarkable candidates for disruptive nanoelectronic devices. Electrons can flow through them ballistically, which means that they travel without being scattered by features in the material of the nanotube. It is possible to make transistors with single walled nanotubes with both electron and hole conductors, thus providing components for complete logic circuits. It is even possible to make transistors which work with a change of only a single electron in the active region. All of this could be very significant for future electronics applications, but that would be only the beginning, because these devices use only the charge on the electron. There is another secret weapon which can be used, in the form of the electron spin.The electron spin can be thought of as a tiny magnet, which can point in one of two directions (often referred to as up and down). The new field of electronics which this opens up already has a name, spintronics, and its own Nobel Prize Winners. The biggest current application of spintronics is in the heads for reading data on hard discs in computers, revolutionizing this multibillion dollar industry. Magnetic random access memory is now being made and sold, with the promise of ever higher access speeds. The search is on for new materials systems which can be used for spintronic devices, which may in turn be exploited in new applications. New effects are being discovered all the time. For example, if you apply different temperatures to the two ends of a metallic magnet, a current of electron spins can flow.Our vision is to put spin into carbon nanoelectronics. If we can do this, we may be able to add a whole new capability to what is already possible with nanotube transistors. For this purpose we shall use other carbon materials, even smaller than nanotubes, in the form of cages called fullerene molecules (also known as Bucky balls). These molecules can each contain one or more atoms which carry a resulting electron spin. They can be inserted into single walled nanotubes, and the resulting structures are sometimes called peapods, because that is what they look like in an electron microscope. Peapods provide an ideal way to put spin into nanotubes.In our research programme, we shall fabricate peapod transistors, and look at them by high resolution transmission electron microscopy under conditions which minimise the damage to the samples. In this way we shall be able to see with atomic resolution the very piece of material which is active in the device. We shall measure the current through the transistor while we vary the magnetic field and the temperature, and look for effects which may be very sensitive to one or other of these. We shall apply microwave radiation, and detect the effect on electrical conductance as we sweep the magnetic field through the spin resonance. Finally we shall perform controlled experiments to measure electrically the direction of the spin.Although these are fundamental experiments, our hope is that they will lead to practical applications. These may be through the effects of collective excitations, for applications such as nanoelectronic circuits and sensors, or they may be through direct control of the spin states, for more revolutionary devices such as quantum logic devices, quantum memories and perhaps even eventually quantum computing.
Publications
Greplova E
(2017)
Conditioned spin and charge dynamics of a single-electron quantum dot
in Physical Review A
Schaffry M
(2011)
Creating nuclear spin entanglement using an optical degree of freedom
in Physical Review A
Sadeghi H
(2016)
Cross-plane enhanced thermoelectricity and phonon suppression in graphene/MoS 2 van der Waals heterostructures
in 2D Materials
Ramsay A
(2010)
Damping of Exciton Rabi Rotations by Acoustic Phonons in Optically Excited InGaAs / GaAs Quantum Dots
in Physical Review Letters
Gil-RamÃrez G
(2018)
Distance Measurement of a Noncovalently Bound Y@C82 Pair with Double Electron Electron Resonance Spectroscopy.
in Journal of the American Chemical Society
Gehring P
(2017)
Distinguishing Lead and Molecule States in Graphene-Based Single-Electron Transistors.
in ACS nano
Li Y
(2017)
Double quantum dot memristor
in Physical Review B
Robertson AW
(2013)
Dynamics of single Fe atoms in graphene vacancies.
in Nano letters
Schaffry M
(2010)
Entangling remote nuclear spins linked by a chromophore.
in Physical review letters
Sowa JK
(2017)
Environment-assisted quantum transport through single-molecule junctions.
in Physical chemistry chemical physics : PCCP
Description | Single nanotube quantum devices |
Exploitation Route | Carbon-based quantum technologies |
Sectors | Digital/Communication/Information Technologies (including Software) Electronics Manufacturing including Industrial Biotechology |
URL | http://andrewbriggs.org |
Description | Quantum of Spin |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Public/other audiences |
Results and Impact | The Quantum of Spin exhibit was the largest and among the most successful of the many exhibits at the Royal Society Summer Science Exhibition in 2012. Over the course of 1 week from 3 to 8 July, our team explained their research to over ten thousand visitors. |
Year(s) Of Engagement Activity | 2012 |
URL | http://sse.royalsociety.org/2012/exhibits/ |