Accelerated electrons enable ‘extraordinarily strong’ negative refraction

Accelerated electrons enable ‘extraordinarily strong’ negative refraction: Researchers at the Harvard School of Engineering and Applied Sciences (SEAS), collaborating with the Weizmann Institute of Science in Israel, have demonstrated a new way of achieving negative refraction in a metamaterial — as large as -700, more than a 100 times larger than most previously reported...
The underlying physics of previous work in this field has often involved an entity called magnetic inductance. Ham’s research group instead explored kinetic inductance, which is the manifestation of the acceleration of electrons subjected to electric fields, according to Newton’s second law of motion...


To obtain the large kinetic inductance, Ham and Yoon’s work employs a two-dimensional electron gas (2DEG), which forms at the interface of two semiconductors, gallium arsenide and aluminum gallium arsenide...
The resulting movements of electrons in these strips were “felt” by the neighboring strips to the right, where electrons are consequently accelerated.
In this way, the proof-of-concept device propagates an effective wave to the right, in a direction perpendicular to the strips, each of which acts as a kinetic inductor due to the electrons’ acceleration therein. This effective wave proved to exhibit what the researchers call a “staggering” degree of negative refraction.