Many natural and social phenomena fall into the category of stochastic phenomena. However, some of these phenomena are inherently stochastic, while others are stochastic because of our inadequate knowledge of them. Atom decay belongs to the former and traffic congestion or weather patterns fall into the latter.
Simulating the behavior of these stochastic processes is essential for the advancement of science and technology. For this purpose, the behavior of the system is first studied in the individual time steps and then its future behavior is simulated using the information of past steps. Therefore, due to the large amount of information to be stored in this process, memory becomes a key component.
Now researchers have been able to reduce the amount of memory needed in stochastic simulation by quantum information processing. In fact, quantum information processors can store past information in memory states which are not completely distinguishable from one another. As a result, a quantum simulator needs less memory than its classical counterpart. Researchers have reported that a quantum stochastic simulator can encode the required information in fewer dimensions than any classical simulator. This study demonstrates a decrease in memory size beyond the classical limits.
The memory of this quantum simulator consists of photons. The experiment was demonstrated for a simple system, but it can be extended to large-scale problems and varied stochastic processes.
Source: PHYSICAL REVIEW X