John M. Martinis is an experimental physicist whose work laid much of the foundation for superconducting quantum circuits. Trained at the University of California, Berkeley, he carried out landmark experiments demonstrating macroscopic quantum tunneling and energy quantization in Josephson-junction circuits, showing that electrical circuits can exhibit fully quantum behavior. As a long-time research scientist at NIST and professor at UC Santa Barbara, he developed high-coherence superconducting qubits and precision measurement techniques that became standards in the field. He later led Google’s quantum hardware program, where his team built and operated large-scale superconducting processors and demonstrated quantum computational advantage. More recently, he co-founded Qolab, focusing on scalable, high-performance quantum hardware. His contributions to macroscopic quantum phenomena and superconducting quantum technology were recognized with the 2025 Nobel Prize in Physics.