Mechanical Schrödinger's Cat ⚡ экспресс
We consider the generation of macroscopic quantum superpositions in a nanomechanical resonator coupled to a coherently driven two-level system via transverse and longitudinal interactions. Driving the qubit at twice the oscillator frequency activates resonant two-phonon exchange processes, allowing coherent conversion of pump energy into phonon pairs with subsequent dissipative stabilization. By perturbatively eliminating the lossy qubit from the full time-dependent Hamiltonian, an effective master equation for the mechanical mode is derived. The reduced dynamics include engineered two-phonon loss and a coherent squeezing term, together guiding the resonator into a deterministic Schrödinger's cat state. The method uses only a single driven qubit without an auxiliary resonator, offering a scalable and experimentally feasible route to macroscopic quantum superpositions in platforms such as circuit quantum electrodynamics.
A child's swing cannot move forward and backward at the same time. But physicists propose a method for a nanostring — a mechanical resonator. They connect a qubit (an artificial atom) to it and drive it with an electrical signal at twice the string's natural frequency. This makes the string oscillate in two opposite directions at once — just like the famous Schrödinger's cat, only mechanical.
Surprisingly, energy losses don't harm but help: they stabilize this weird state. It's akin to how an increase in entropy (disorder) in open systems sometimes leads to order. To verify it, they use spectroscopy — a precise vibration analysis, much like tuning a musical string by ear.
The method is far simpler than previous ones: no bulky traps or numerous instruments. Just one qubit and a resonator. The largest object for which quantum superposition was previously observed was a molecule of 2000 atoms. Here, we have a string made of billions of atoms — a true quantum giant. Such states will open the door to sensors of incredible precision and robust quantum computing.
🎯 In 2019, scientists cooled a nanostring to a state where it completely stopped trembling from heat.
🎬 Schrödinger's cat states are often played with in science fiction — from stories of reality splitting to quantum computers of the future.