2013 Isaac Newton medal of the Institute of Physics
Sir John Pendry, Blackett Laboratory, Imperial College London. For his seminal contributions to surface science, disordered systems and photonics.
John Pendry has made seminal contributions to the theory of surfaces and of low energy electron diffraction, but his most recent work has probably had the greatest impact scientifically and certainly on the public imagination. He has introduced a new class of materials, metamaterials, whose electromagnetic properties depend on their internal structure rather than their chemical constitution. They expand massively the material parameters available throughout the electromagnetic spectrum from the visible down to DC fields. Pendry’s ‘perfect lens’ is a remarkable example of the revolutionary nature of metamaterials, with its resolution limited only by the perfection of manufacture and not by the wavelength. His most recent innovation of ‘transformation optics’ has been extensively deployed to design metamaterial devices, most famously the invention of a ‘cloak of invisibility’ that has attracted worldwide public interest.
Metamaterials have enabled the phenomenon of negative refraction to be realised in practice. Negative refraction was postulated decades earlier by Veselago, but no examples were ever found in nature. Pendry showed how a metamaterial could be constructed that would display negative refraction. Moreover, he discovered that a lens manufactured from negatively refracting material would circumvent Abbé’s diffraction limit to spatial resolution, which has stood for more than a century. In this way he gave the first prescription for a ‘perfect lens’. Transformation optics has similarities to the general theory of relativity and gives the metamaterial specifications required to rearrange electromagnetic field configurations at will. It does this by representing the field distortions as a warping of the space in which they exist. In its simplest form the theory shows how we can direct field lines around a given obstacle and thus provide a ‘cloak of invisibility’.