Quantum mechanics was developed to describe the physics of the small, for fundamental particles, atoms and molecules. But does it still work for macroscopic systems? My PhD thesis experiment in 1985 tested this idea, showing the macroscopic current and voltages in a 1 cm chip obey the quantum phenomena of tunneling and energy-level quantization, proving that a superconducting circuit can behave as a single `artificial atom.’ Over the last four decades, many physicists around the world have continued research on quantum devices. The field has evolved from fundamental tests into a high-stakes effort to build quantum bits and a quantum computer. At Google, our 'quantum supremacy' experiment was the culmination of this system-level optimization, proving that a processor could outpace classical supercomputers by maintaining high-fidelity control over a huge computational (Hilbert) space. Now, at my startup Qolab, we are leveraging 300mm semiconductor fabrication to achieve the extreme uniformity and yield necessary to build a useful general-purpose quantum computer.
Bio: 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.