“It is hardly original to work at the nanometer scale,” says Gabriel Aeppli, who is the Quain Professor of Physics at University College London (UCL). Molecular biology has been engineering at the nanoscale for many years, he explains, and chemistry and physics have long surpassed limits measured in nanometers. Aeppli's statement could be considered surprising, since he is the director of the new London Centre of Nanotechnology (LCN). After all, an eight-storey building is being constructed in central London at a cost of approximately £12.5 million to the UK government, research councils, and the Wolfson Trust. But this is not to say Aeppli doesn't have a clear vision for what nanotechnology can achieve.
“Nanotechnology is not a holy grail in itself. Rather, nanotechnology is a toolkit that has emerged from the semiconductor industry,” explains Aeppli. Using this pragmatic definition, he names two challenges. The first is to apply the tools to new areas, for example healthcare and the environment. The second is to continue making progress in information technology, which depends on maintaining and expanding the nanotechnology toolkit.
These two challenges are reflected in Aeppli's own research. One area of his work focuses on applications of nanotechnologies in biomedicine. “The aim is to develop more sophisticated analytical tools that can be introduced into daily medical practice,” he explains. Aeppli is part of a group including photonics researchers and biologists that is developing chip-based systems for detecting untreated DNA or proteins in small amounts, i.e. label-free diagnostics.
The other large focus of Aeppli's work centers on quantum magnetism and quantum information processing (QIP). These areas involve the exploitation of the quantum mechanical properties of matter at the nanoscale. In magnetism, Aeppli explains, once the quantum idea of spin has been accepted, ferromagnetic behavior can be described in entirely classical terms. However, in some material systems, the quantum nature of magnetism is important even for groups of spins. He uses the same picture to explain the relation of quantum computers to standard, digital PCs. Bits, which are either 0 or 1 in value, can be considered as classical objects in the design of conventional systems. However, when bits are generalized to quantum bits or ‘qubits’, they can be a superposition of the 0 and 1 states. “Quantum computing, in essence, is what is enabled when coupled elements display quantum behavior.” Aeppli and coworkers at LCN are working to demonstrate quantum computing in solid-state systems at high-temperature. The goal is to base such a computer on a Si architecture, making use of standard semiconductor fabrication technology. Again, the emphasis is on using a set of nanofabrication tools to enable novel devices.
Aeppli's research on quantum magnetism has recently been recognized by the 2005 Oliver E. Buckley Prize, the American Physical Society's premier award in condensed matter physics. Aeppli shares the honor with Myriam Sarachik of the City College of New York and David Awschalom of the University of California, Santa Barbara. While the three investigators are not collaborators, Aeppli says they go a long way back together and their independent investigations have covered complementary aspects of quantum magnetic systems.
The LCN is currently taking up most of Aeppli's time, with the purpose-built facility on course for completion in the Fall. A joint venture by UCL and Imperial College London, the center will bring together the expertise of around 30 principal investigators from the physical and life sciences, medicine, and engineering. Research will be organized around three application-oriented areas – novel, low-cost healthcare; new paradigms for information technology; and earth, energy, and the environment – and not by discipline or technique. It is clear that this is not about to be an ivory tower of research. Although he stresses that the three areas present large intellectual challenges – the key to their academic appeal – Aeppli is quick to emphasize the center's business development plans. LCN is focusing on a set of deliverables that include immunocompatible biotissues, low-cost solar cells, and compact fuel cells. Realization of these deliverables is to be managed with a clear emphasis on exploitation and commercialization.“This makes us unique in the UK and elsewhere,” comments Aeppli?In order to achieve these goals, the LCN has targeted areas where it needs to build a presence by hiring new staff. An offer has been made to a US biophysicist and very strong candidates have been found to fill positions in quantum devices and theory, says Aeppli. “We have done very well on the recruiting front.”
[1] Aeppli has high aspirations for the new center. And, once more, it is all about nanotechnology as a toolkit to enable applications. “I will be happy if we produce a hit like giant magnetoresistance read heads or nanoparticle-based pregnancy tests, or even a Nobel Prize,” he says.