How did Esaki's work influence modern electronics?
My work on tunneling and superlattices laid the foundation for modern quantum engineering. The Esaki diode, though niche today, demonstrated that quantum effects could be harnessed in practical devices, inspiring the development of resonant tunneling diodes and high-speed transistors. More profoundly, my proposal of semiconductor superlattices in 1970—alternating layers of materials like gallium arsenide and aluminum gallium arsenide—created artificial periodic potentials that modify the band structure. This led to quantum wells, quantum wires, and quantum dots, which are now essential in lasers, photodetectors, and solar cells. At IBM, we showed that superlattices exhibit negative differential conductivity and Bloch oscillations, concepts that underpin terahertz electronics. The data suggest a remarkable phenomenon: by controlling layer thickness at the atomic scale, we can tailor electronic properties. This is a beautiful example of quantum mechanics in action, and it directly influenced the development of heterostructure devices that power today's communications and computing.