New ‘physics shortcut’ lets laptops tackle quantum problems once reserved for supercomputers and AI
Physicists have developed a modeling method quantum systems on everyday computers, making it easier to run complex simulations without relying on supercomputers or artificial intelligence (AI) tools.
The new method updates the “truncated Wigner approximation” (TWA), a decades-old technique for approximating quantum behavior, into a plug-and-play shortcut for solving complex calculations.
“Our approach offers significantly lower computational cost and a much simpler formulation of dynamic equations,” study co-author Jamir Marinassistant professor of physics at the State University of New York at Buffalo, said in a statement statement. “We believe that this method could, in the near future, become the main tool for exploring this type of quantum dynamics on consumer computers.”
A modern take on a semi-classic
First developed in the 1970s, TWA is a “semi-classical” simulation method used to predict quantum behavior.
Quantum systems are governed by the rules of quantum mechanics and typically involve particles at incredibly small scales. At this level, phenomena such as coherence and tangle produce effects that cannot be fully explained by classical physics alone.
Because these effects generate a very large number of possible outcomes, simulating them often requires massive computing power. supercomputer AI clusters or networks. To facilitate the study of quantum dynamics on conventional hardware, physicists often use a theoretical framework called semiclassical physics.
Semiclassical physics involves treating parts of a quantum equation through the lens of quantum mechanics and other parts of classical physics, allowing researchers to evaluate the behavior of a quantum system over time.
TWA works by transforming a quantum problem into several simplified classical calculations, each starting with a small amount of statistical “noise” to account for the uncertainty inherent in quantum mechanics. By performing these simplified calculations and averaging the results, researchers get a sufficient picture of how the quantum problem would play out.
However, TWA was initially developed for “idealized” quantum systems completely isolated from external forces. This makes the calculations much more manageable because it assumes that the system evolves without interference.
In reality, quantum systems are often open and exposed to external interference. Particles lose or absorb energy, or gradually lose coherence as they interact with their environment. These effects, known collectively as dissipative dynamicsfall outside the scope of conventional TWA and make it much more difficult to predict the behavior of quantum systems.
Researchers solved this problem by extending TWA to handle Lindblad’s main equations — a mathematical framework widely used to model dissipation in “open” quantum systems. They then integrated the updated method into a “practical, user-friendly model” that serves as a conversion table, allowing physicists to solve a problem and obtain usable equations in a matter of hours.
“A lot of groups have tried to do this before us,” Marino said. “It is known that some complex quantum systems could be solved efficiently with a semi-classical approach. However, the real challenge has been to make it accessible and easy to achieve.”
The updated technique also makes TWA reusable. Rather than having to rebuild the underlying mathematics from scratch for each new problem, physicists can input their system parameters into the updated framework and apply them directly. This lowers the barrier to entry and significantly speeds up calculations, the team said.
“Physicists can basically learn this method in a day, and by about the third day, they are solving some of the more complex problems that we present in the study,” co-author of the study. Oksana Chelpanovaa doctoral student at the University at Buffalo, said in the release.
