NSQI: Research
The Bristol Centre for Nanoscience and Quantum Information (NSQI): Current Research
The Centre for NSQI is a multidisciplinary research facility, a research hub and catalyst for creative interactions between scientists across the University in the fields of nanoscience and quantum information. In the story of SQI, the building, which opened its doors in September 2009, is a main character. Boasting one of the quietest rooms in the world, the building is designed to meet the strictest needs of those doing research at the nanoscale. The vibration levels measured in the basement are among the lowest measured in academic research buildings, setting the bar at least one order of magnitude lower than the newly published NIST standard criterion.
Other features enabling ground-breaking NSQI research include bespoke vibration isolation concrete pads, electromagnetic shielding, direct current LED lighting, fully controllable low power air handling, climate control, acoustic isolation, independent electrical earthing, low dust environment, and class 1000 clean rooms. Researchers in NSQI also benefit from a range of scientific support services: specialised laboratory managers with expertise in chemical and biochemical, wet laboratory technologies, low noise and probe microscopy instrumentation, clean room environment and micro and nanofabrication technology.
The philosophy underpinning the Centre's design and operation is to bring together scientists from vastly different, yet complementary backgrounds for experimental and theoretical exploration. Whether this arises from planned or serendipitous encounters, this meeting of minds is essential for innovative and transformative interdisciplinary science. In order to stimulate lively discussion and collaboration, the Centre has rooms such as the glass-walled "fish bowl" and the QI study room - as well as a welcoming coffee area - inviting researchers to participate and share their intellectual wealth and scientific culture. The Centre can be thought of as a “research hotel” - after a brief health and safety check-in, reservations are possible but by no means obligatory!
1 Enhancing efficient solar electricity production (Dr Neil Fox, Chemistry Department)
A novel material made of nanoscale diamonds is being developed that will enable an efficient and environmentally friendly way of producing electric power. The material’s unique properties will enable the sun’s radiation power to be converted directly into electricity.
Dr Neil Fox and his team, which include physicists and engineers, has developed a patented route by which diamond powders can be doped reproducibly with lithium – yielding an electron emitter material that exhibits turn-on voltages lower than 1 Volts/ micron and can operate successfully under substantially poorer vacuum conditions than rival field emitters ( e.g. carbon nanotubes). Emissive diamond powders also constitute a low cost nanomaterial for use in direct energy conversion (thermionic solar power generation), and microplasma generators. There are also potential applications in high temperature electronics, photovoltaics and photodetectors.
The key advance resides in the enhancement of the efficient thermionic conversion of sunlight into electrical power. Nanodiamonds are one of the few materials that can absorb heat, and emit thermionic electrons which, if harvested, can generate electrical power. Due to the exceptional stability of the NSQI environment, Fox hopes to achieve unprecedented nanoscale control on the characterisation and fabrication of the required diamond dust.
2 Using Light to apply forces to small objects (Professor Mervyn Miles, Physics Department)
Using the field generated by the holographic projection of laser light, Professor Mervyn Miles, head of the Nanophysics and Soft Matter Group, has designed a new instrument, a dynamic holographic assembler, capable of manipulating physical and biological objects with very soft forces - a light touch. Miles and his team have developed a powerful yet intuitive user interface that enables the manipulation of biological cells, including the palpation of cancer cells as they undergo differentiation.
The dynamic holographic assembler (DHA) is being developed principally as a new technology for the assembly of functional devices using components from the micrometre scale to the tens of nanometres scale. The particles are manipulated with optical traps, which use the force gradient associated with a tightly focused beam of light to attract particles towards the highest optical intensity. Until recently, the focusing was achieved using in the objective lens of an optical microscope. In the last few years, spatial light modulators (SLMs) have been used to construct dynamic holograms, that are used to generate and manipulate multiple tightly-focused beams of laser light in three dimensions in which microscopic particles can be trapped and positioned.
An important innovation of the project is the concept of nanotools that can be constructed from three interconnected silica beads. When optically-trapped, the beads provide the translational and rotational control of the nanotool. The active element of the nanotool is rigidly located to bead formation and can be brought up to the structure on which it will operate. The active element may be simply a nanorod to physically manipulate the structure or it may be chemically or biologically active by incorporating, for example, a catalyst or an enzyme.
This ground-breaking technology will enable novel research in molecular, cellular and systemic biology, and has already been instrumental in generating novel material for quantum photonics researchers.
3 Quantum Computing Using Photons (Professor Jeremy O'Brien, Centre for Quantum Photonics)
Quantum mechanics describes how nature behaves at its most fundamental level. Understanding its unusual properties - such as superposition and entanglement - has been an important topic of research since the theory's development early last century. Quantum information science has emerged over the last two decades to consider whether this behaviour could be useful. It addresses the question: What additional power or functionality can be achieved in encoding, transmitting and processing information by using uniquely quantum mechanical behaviour?
Anticipated future quantum technologies include quantum communication, which offers perfectly secure communication; quantum metrology, which allows more precise measurements than could ever be achieved without quantum mechanics; quantum lithography, which could enable fabrication of devices with features much smaller than the wavelength of light; and quantum computing, which promises exponentially faster computation for particular tasks.
Photons make excellent quantum bits or qubits (two level quantum systems) since they are well isolated from the environment and their quantum mechanical state can be easily manipulated. Professor Jeremy O'Brien, head of the Centre for Quantum Photonics, which spans the Department of Physics and Department of Electrical and Electronic Engineering, and his team have constructed a primitive quantum computer, the first of its kind, in which photons propagate through a silicon chip. Performing the factorisation of numbers into their prime divisors as an example of a computationally-onerous mathematical calculation, this is a major step forward towards a quantum computer with immense computing power.
