Four-dimensional Bell state measurement assisted by polarization and frequency degrees of freedom

Bell state measurement plays a pivotal role in the realm of quantum communication, yet a definitive solution for achieving complete Bell state measurement remains unclear. In this paper, we propose a theoretical scheme for four-dimensional orbital angular momentum Bell state measurement, harnessing the polarization and frequency degree of freedom as auxiliary tools. Within this scheme, the input state traverses a hyperentangled state analyzer comprised of quantum logic gates, ultimately enabling the realization of Bell state measurement in a four-dimensional mode. Simultaneously, serving as a novel avenue to enhance the capacity of quantum communication, this scheme has potential applications in realizing large-capacity quantum communication.