Taylor Michael A D, Mandal Arkajit, Zhou Wanghuai, Huo Pengfei
Department of Chemistry, University of Rochester, Rochester, New York 14627, USA.
The Institute of Optics, Hajim School of Engineering, University of Rochester, Rochester, New York 14627, USA.
Phys Rev Lett. 2020 Sep 18;125(12):123602. doi: 10.1103/PhysRevLett.125.123602.
This work provides the fundamental theoretical framework for molecular cavity quantum electrodynamics by resolving the gauge ambiguities between the Coulomb gauge and the dipole gauge Hamiltonians under the electronic state truncation. We conjecture that such ambiguity arises because not all operators are consistently constrained in the same truncated electronic subspace for both gauges. We resolve this ambiguity by constructing a unitary transformation operator that properly constrains all light-matter interaction terms in the same subspace. We further derive an equivalent and yet convenient expression for the Coulomb gauge Hamiltonian under the truncated subspace. We finally provide the analytical and numerical results of a model molecular system coupled to the cavity to demonstrate the validity of our theory.
这项工作通过解决电子态截断下库仑规范和偶极规范哈密顿量之间的规范模糊性，为分子腔量子电动力学提供了基本的理论框架。我们推测这种模糊性的出现是因为并非所有算符在两个规范的同一截断电子子空间中都受到一致的约束。我们通过构造一个酉变换算符来解决这种模糊性，该算符能在同一子空间中恰当地约束所有光与物质的相互作用项。我们进一步推导了截断子空间下库仑规范哈密顿量的一个等效且方便的表达式。最后，我们给出了一个与腔耦合的模型分子系统的解析和数值结果，以证明我们理论的有效性。
