Researchers at the Indian Institute of Science (IISc) have addressed the problem of maximizing the efficiency of a quantum circuit by using a mathematical analogue. They devised an algorithm to explicitly count the number of computing resources necessary, and optimized it to obtain maximum efficiency.
The most efficient circuit does not minimise the error in the output; rather it minimises the resources required for obtaining that same output. The results also appear to link the efficiency optimization problem with string theory, a famous idea that tries to combine gravity and quantum physics to explain how the universe works.
The paper has been published in Physical Review Letter.