Locally optimized variational evolution for quantum many-body systems
Simulating quantum systems by tracking only what you can actually measure
Physicists have developed a new method for simulating quantum systems that sidesteps the astronomical computational cost by focusing on local properties instead of the entire quantum state. The approach works because in many real quantum systems, local measurements—like temperature at a specific point—don't actually depend on the full microscopic details of the whole system, especially once it reaches thermal equilibrium. The team demonstrated the method on current quantum computers, showing it can capture the right physics while being practical enough to run on noisy hardware.
Current quantum computers struggle with simulating large quantum systems because tracking the complete state grows exponentially harder with size. By targeting only the local properties people actually care about measuring—temperatures, pressures, energy flows—this method cuts through that complexity. The approach works on today's real quantum hardware despite their noise and errors, opening a path to using current machines for practical simulations before we have perfect quantum computers.