00000ctm a22000004i 4500 UP-99796217613118198 Buklod 20191014090407.0 m |o d | ta 191014s2016 xx d r |||| u| (iLib)UPD-00414266047 DARCHIVES rda eng DMLUC LG 995 2016 P51 A48 Advincula, Janus B. author. Almost non state-altering POVM quantum measurement Janus B. Advincula ; Eric A. Galapon, adviser. Quezon City Institute of Physics, College of Science, University of the Philippines Diliman 2016. viii, 34 leaves illustrations 28 cm. text rdacontent unmediated rdamedia volume rdacarrier Thesis (M.S.-Applied Physics) --University of the Philippines Diliman June 2016. Thesis is available to the public. The measurement process of a quantum system interacting with the measuring apparatus is properly described by positive operator-valued measures or POVM's. It provides the most general description of quantum measurement. In this thesis, we mathematically prove that, for invertible density matrices, there are no POVMs that leave the quantum state completely unaltered after measurement. Furthermore, for a given POVM and initial density matrix, there is a minimum amount of disturbance that a measurement imparts to the quantum state.This disturbance may be measured by the trace distance between the initial and final density matrices. Lastly, this trace distance is bounded below by the absolute value of the eigenvalue differences of the initial and final density matrices. We've also worked out the minimal state-altering POVM for two-level systems or qubits. Quantum systems. Operator-valued measures. Galapon, Eric A. adviser. FI UPD DARCHIVES LG 995 2016 P51 A48 Thesis