Is there a general way to describe the role of memory in quantum thermodynamics? This was the question that guided Zambon’s doctorate.
The study of thermodynamics from a non-Markovian perspective was not something new. Previous results already showed the application of the concept to subatomic systems – but only in specific cases that could not be extended to other scenarios. What the researcher proposed in his article was the generalization of this technique, with the goal of showing how it would be applicable to general cases of quantum physics.
Quantum physics, in general, analyzes systems based on spot measurements – like photographs that freeze instants. To overcome this condition, Zambon proposes the use of a new tool: process tensors. This mathematical tool makes it possible to describe the evolution of the quantum system. With its help, it is possible to map the transformations that occur over time.
These “photos” represent the moments in which physicists conduct operations on the system. When operations cease, it is assumed that the environment is transforming. “When I turn off my operation, the environment turns on its. And so on,” Zambon explains.
“This is something that has been done for a long time,” Zambon points out. “But it was assumed that these operations of the environment on the system were not correlated,” he continues. The physicist explains that, previously, it was considered that the phenomena were independent of each other – which is only true for Markovian systems.
“If the dynamics are non-Markovian, the action of the environment on the system is a sequence of interleaved and connected operations,” he clarifies. And the process tensor is the mathematical object that represents this sequence of connected transformations in the evolution of the quantum system. “Its application results in the most complete analysis possible.”
