Magnetic Vortex Becomes a Quantum Bit express

Original: "Quantum Coherence in Superconducting Vortex States"
arXiv:2510.19769 · 2025-10-22 · CC BY 4.0 · 1 min
In granular superconductors, magnetic vortices behave like two-state quantum systems.

Magnetic vortices in superconductors, like whirlpools in water, typically scatter energy and quickly vanish due to internal friction — dissipation. This hampers their use in quantum chips. But in a film of tiny aluminum grains, a vortex gets trapped and resembles a whirlpool in a narrow well: it spins either one way or the other. Quantum nature allows it to spin both ways at once until measured. This double life lasts for milliseconds — an eternity in the micro-world. Scientists have learned to flip the vortices with microwave pulses (spectroscopy) and read out their state without loss. Each vortex carries exactly one quantum of magnetic flux — a billionth of Earth's field. The idea of Alexei Kitaev to use such structures for noise-tolerant quantum computing has been directly confirmed.

Each such vortex carries just one quantum of magnetic flux — about a billionth of Earth's magnetic field.

Scientists
Christian DopplerD. B. McLaughlinDidier QuelozMichel MayorR. A. RossiterWolfgang Pauli
Concepts
magnetic vortex superfluid vortex quantum vortices superconducting wire semiconductor qubits superconducting electronics thin film superconductivity superconductivity zero resistance flux pinning quantum superfluidity exciton condensate flux quantization phase fluctuations cuprate pseudogap bcs theory microwave pulse superfluid stiffness high temperature superconductor