New Framework Reveals How Symmetry Shapes Quantum System Complexity
Researchers have developed a mathematical tool that explains how symmetries control the evolution of quantum operators over time. The discovery could accelerate development of quantum computers and improve understanding of thermalization in quantum materials, with direct applications to quantum simulation and materials design.
Originaltitel: Growth of block-diagonal operators and symmetry-resolved Krylov complexity
<p>This work addresses how the growth of invariant operators is influenced by their underlying symmetry structure. For this purpose, we introduce the symmetry-resolved Krylov complexity, which captures the time evolution of each block into which an operator, invariant under a given symmetry, can be decomposed. We find that, at early times, the complexity of the full operator is equal to the average of the symmetry-resolved contributions. At later times, however, the interplay among different charge sectors becomes more intricate. In general, the symmetry-resolved Krylov complexity depends on the charge sector, although in some cases this dependence disappears, leading to a form of Krylov complexity equipartition. Our analysis lays the groundwork for a broader application of symmetry structures in the study of Krylov space complexities with implications for thermalization and universality in many-body quantum systems.</p>