A Unified Scheme of Measurement and Amplification Processes based on Micro-Macro Duality -- Stern-Gerlach experiment as a typical example

摘要

A unified scheme for quantum measurement processes is formulated on the basisof Micro-Macro duality as a mathematical expression of the general idea ofquantum-classical correspondence. In this formulation, we can naturallyaccommodate the amplification processes necessary for magnifying quantum statechanges at the microscopic end of the probe system into the macroscopicallyvisible motion of the measuring pointer. Its essence is exemplified andexamined in the concrete model of the Stern-Gerlach experiment for spinmeasurement, where the Helgason duality controlling the Radon transform is seento play essential roles.