Microwave amplification to 2.5 GHz in a quantum state transfer device

Abstract
Reflection amplification has been demonstrated from 40 MHz to 2.5 GHz using a bilevel superlattice structure known as a quantum state transfer device. Measurements of the magnitude and phase of the voltage reflection coefficient were made at 300 K using a specialized microwave probe. The maximum normalized gain, at 40 MHz, approaches the gain expected from dc measurements of the negative differential resistance.