Quantum Cat Made of 120 Photons ⚡ экспресс
Quantum "cat states" — superpositions of two opposite macrostates — are important for exploring the boundary between the quantum and classical worlds, as well as for ultra-precise measurements and fault-tolerant computing. Creating them on a large scale is hindered by decoherence. This work proposes a method based on the dynamic invariant of hybrid qubit-boson systems with a time-dependent Hamiltonian. It enabled the generation of states with more than 120 photons and a fidelity above 0.962. This approach, like a master conductor, orchestrates the system's evolution, paving the way to macroscopic quantum engineering.
The quantum cat is a state of light proposed by Schrödinger: photons behave like a spinning coin, seen as both heads and tails at once. Physicists have created such a 'coin' from 120 photons, racing at the speed of light in a light trap. Usually, a large system quickly collapses into one option due to increasing disorder (entropy).
The solution proved elegant: a quantum switch (qubit) was coupled with the light and a mathematical trick was applied that naturally maintains balance. Even with noise, accuracy exceeded 96%, and without noise the method is flawless. Astonishingly, the previous record of 40 photons has been tripled. Such large cats will help probe the boundary between quantum wonders and the familiar world, and also serve as ultra-sensitive sensors and the basis for fault-tolerant quantum computers, building on the work of von Neumann. The assessment of duality comes from a special technique invented by Wigner.
🎯 The previous record for cat light was about 40 photons. The new result triples that number.
🎬 In 'The Quantum Thief' by Hannu Rajaniemi, quantum states store identities—large cat states could be a step toward such exotica.