Speaker: Professor Sir John Brian Pendry

Time: 4:00 pm - 5:30 pm, July 26, 2023

VooV ID: 218-464-798; 131-163-773 (Simulcast)

About the Speaker: 

Professor Sir John Pendry is a condensed matter theorist andbegan his career in the Cavendish Laboratory.Cambridge, followed by six years at theDaresbury Laboratory where he headed the theoretical group. He has worked extensively onelectronic and structural properties of surfaces developing the theory of low energy diffractionand of electronic surface states. More recently he turned his attention to photonic materialsthis interest led to his present research into the remarkable electromagnetic properties ofmaterials where the normal response to electromagnetic fields is reversed, leading tonegative values for the refractive index. In collaboration with scientists at Marconi hedesigned a series of metamaterials, completely novel materials with properties not found innature. These designs were subsequently the basis for new concepts with radicalconsequences, such as the first material with a negative refractive index and a prototypecloaking device, which have both caught the imagination of the world's media. His latest workthe subject of the current talk, is on media whose structure depends on time.

About the Lecture: 

Spatial structure as in photonic crystals and metamaterials strongly influences wavepropagation. Now interest has turned to structure which changes in time on a scalecomparable to the period of incident waves. Many phenomena are revealed such as newamplification mechanisms, quantum effects including models for Hawking radiationconservation laws applying to photon/phonon number, and more.