Overview

• The Royal Swedish Academy of Sciences awarded the 2025 prize for demonstrating macroscopic quantum tunneling and energy quantization in an electrical circuit.
• In 1984–1985 at UC Berkeley, the trio used a superconducting circuit with a Josephson junction to probe quantum effects at macroscopic scale.
• The setup produced a small but clear voltage across an insulating barrier, providing direct evidence of tunneling.
• Measurements also revealed discrete energy levels in the circuit, matching quantum-mechanical predictions.
• The committee said the results underpin prospects for quantum computers, cryptography and sensors, and the laureates will share 11 million SEK.