New Approach to Quantum Mean-Field Theory Proposed

In a recent paper titled Density-Matrix Mean-Field Theory, authors Junyi Zhang and Zhengqian Cheng propose a novel approach to mean-field theories in quantum physics. The paper, available on arXiv, introduces the density-matrix mean-field theory (DMMFT), which aims to address the limitations of conventional mean-field theories that often fail to capture quantum fluctuations.

DMMFT constructs effective Hamiltonians that incorporate quantum environments influenced by entanglements, which are quantified using reduced density matrices. This method provides a systematic and unbiased way to account for fluctuations and entanglements in quantum ordered phases.

The authors demonstrate that DMMFT can quantitatively assess the renormalization of order parameters due to quantum fluctuations and can also identify topological quantum phases. Furthermore, they discuss potential extensions of DMMFT for systems at finite temperatures and those affected by disorder.

The findings suggest that DMMFT could be particularly useful for exploring unconventional quantum orders, especially in frustrated spin systems in high spatial dimensions. This advancement may enhance the understanding of complex quantum systems and contribute to the development of new materials and technologies in quantum computing and condensed matter physics.

The full paper can be accessed at arXiv:2401.06236.