Electrical and Mechanical Properties of Three-Dimensional Tungsten Nanostructures
Lead Research Organisation:
University College London
Department Name: London Centre for Nanotechnology
Abstract
A focussed ion beam (FIB) can be used to grow thin films of tungsten. This is done by scanning the ion beam (containing gallium ions accelerated to 30 kV) over a tungsten hexacarbonyl precursor gas. The gas molecules are cracked by the ions with the result that tungsten is deposited onto a substrate. The resulting tungsten film is superconducting, with a critical transition temperature of around 5 Kelvin. We will extend the FIB-tungsten growth technique to make a variety of three-dimensional nanostructures and devices. Specifically:(i) We will make superconducting tungsten nanowires of radius less than 10 nm. We will measure the electronic properties of the nanowires to determine if they are behaving as quantum phase slip centres (QPSC). A QPSC is a local non-superconducting region in a nanowire which cannot be suppressed no matter how low in temperature the nanowire is cooled to. (ii) We will make Josephson junctions and superconducting quantum interference devices (SQUIDs). The Josephson junction is the basic building block of all superconducting electronic circuits. Two Josephson junctions in parallel are a SQUID, which is the most sensitive detector of magnetic flux. We will use our three-dimensional FIB growth technique to make a highly sensitive gradiometric pick-up coil coupled to a SQUID. (iii) We will make tungsten thin films of thickness less than 10 nm. These will be patterned into meander lines and used as superconducting single photon detectors (SSPDs). The SSPD is a strong candidate technology for photon detection in quantum communication and quantum computation experiments.(iv) We will study the mechanical properties of vertically-grown nanorods. By oscillating them on a piezo-stage mounted in a scanning electron microscope we will measure their Young's modulus and spring constant. This will allow us to determine their suitability for nanomechanics experiments, including the development of an ultra-sensitive mass balance for single molecule mass detection.
Publications
Li F
(2008)
Zinc Oxide Nanostructures and High Electron Mobility Nanocomposite Thin Film Transistors
in IEEE Transactions on Electron Devices
Li W
(2013)
Three-dimensional nanostructures by focused ion beam techniques: Fabrication and characterization
in Journal of Materials Research
Li W
(2008)
Tunability of the superconductivity of tungsten films grown by focused-ion-beam direct writing
in Journal of Applied Physics
Li W
(2010)
Superconductivity of Freestanding Tungsten Nanofeatures Grown by Focused-Ion-Beam
in Journal of Nanoscience and Nanotechnology
Li W
(2011)
Superconductivity of ultra-fine tungsten nanowires grown by focused-ion-beam direct-writing
in Microelectronic Engineering
Li W
(2010)
Superconductivity of freestanding tungsten nanofeatures grown by focused-ion-beam.
in Journal of nanoscience and nanotechnology
Li W
(2012)
Atomic resolution top-down nanofabrication with low-current focused-ion-beam thinning
in Microelectronic Engineering
Romans E
(2010)
Three-dimensional nanoscale superconducting quantum interference device pickup loops
in Applied Physics Letters
Wang H
(2013)
Model-independent quantitative measurement of nanomechanical oscillator vibrations using electron-microscope linescans.
in The Review of scientific instruments
Description | EPSRC |
Amount | £497,189 (GBP) |
Funding ID | EP/H012192/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start |
Description | EPSRC |
Amount | £382,700 (GBP) |
Funding ID | EP/G061939/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start |
Description | EPSRC |
Amount | £382,700 (GBP) |
Funding ID | EP/G061939/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start |
Description | EPSRC |
Amount | £497,189 (GBP) |
Funding ID | EP/H012192/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start |
Description | EPSRC |
Amount | £1,661,788 (GBP) |
Funding ID | EP/H005544/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start |
Description | EPSRC |
Amount | £1,661,788 (GBP) |
Funding ID | EP/H005544/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start |
Description | Raith gmbh |
Amount | £60,000 (GBP) |
Funding ID | raith-ucl |
Organisation | Raith GmbH |
Sector | Private |
Country | Germany |
Start |
Description | Raith gmbh |
Amount | £60,000 (GBP) |
Funding ID | raith-ucl |
Organisation | Raith GmbH |
Sector | Private |
Country | Germany |
Start |
Description | NPL |
Organisation | National Physical Laboratory |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Scientific research collaboration |
Collaborator Contribution | Scientific research collaboration |
Impact | NPL are formal partners in UCL's EPSRC CDT in Delivering Quantum Technologies |