Superconducting quantum computing

Superconducting quantum computing is a branch of quantum computing and solid state physics that implements superconducting electronic circuits as qubits in a quantum processor. These devices are typically microwave-frequency electronic circuits containing Josephson junctions, which are fabricated on solid state chips.

Superconducting circuits are one of many possible physical implementations of qubits, the quantum computer's equivalent of a traditional bit in a classic computer. Qubits refer to a two-state quantum mechanical system, and have two logic states, the ground state and the excited state, often denoted ${\displaystyle |g\rangle {\text{ and }}|e\rangle }$ (for ground and excited), or ${\displaystyle |0\rangle {\text{ and }}|1\rangle }$. Superconducting quantum computing implementations are categorized as "solid state" quantum computers, where qubits are intrinsically integrated in a solid-state device. Solid state quantum computers also borrow fabrication techniques developed for solid state classical computation.

Superconducting architecture is the dominant method in the industry for developing quantum processing units, or QPUs. Research in superconducting quantum computing is conducted by companies such as Google, IBM, IMEC, BBN Technologies, Rigetti, and Intel. Alternatives to superconducting qubits include trapped ions, and neutral atoms.

Ongoing research in superconducting quantum computing includes device-level improvement, developing error correction methods, and demonstrating quantum advantage by comparing a quantum processor's performance to a classical computer.