Virtual states in the coupled-channel problems with an improved complex scaling method
Yan-Ke Chen, Lu Meng, Zi-Yang Lin, Shi-Lin Zhu
Abstract
We improve the complex scaling method (CSM) to obtain virtual states, which is challenging in the conventional CSM. Our approach solves the Schrödinger equation in momentum space as an eigenvalue problem by choosing flexible contours. It proves to be highly effective in identifying the poles across different Riemann sheets in multichannel scatterings. This approach is more straightforward and efficient than employing the Lippmann-Schwinger equation and using a root-finding algorithm to search for the zeros of the Fredholm determinant. This advancement significantly extends the capabilities of the CSM in accurately characterizing the virtual states in quantum systems. Published by the American Physical Society 2024