Nobel Prize in Physics 2025: Macroscopic Quantum Effects and the Dawn of Quantum Computer

Huge congratulations to John Clarke, Michel H. Devoret and John M. Martinis on the 2025 Nobel Prize in Physics “for the discovery of macroscopic quantum mechanical tunneling and energy quantization in an electric circuit.” Their superconducting Josephson-circuit experiments made quantum effects unmistakably visible at circuit scale, discrete, anharmonic energy levels and coherent tunneling between macroscopically distinct states, laying key groundwork for modern superconducting qubits. In this short computational essay, we’ll walk through compact simulations that reproduce those signatures: a spectroscopy-style level map for the Cooper-pair box/transmon, and time-domain tunneling dynamics with realistic decoherence to mirror the original observations.