Probabilistic and information theoretic interpretation of quantum measurement

Abstract

In this thesis, I have given a brief overview to the answers of two central questions in quantum computation. How much information can be encoded in quantum systems, and how efficiently can this information be extracted. Manipulation of quantum information through manipulating quantum states is relatively well studied topic. This is usually achieved by unitary transformations. In this thesis, after giving a brief overview of fundamentals of quantum computation, basic quantum information theory is briefly discussed. After that, the main question about how to estimate a quantum state has been looked into more carefully. Given a finite ensemble of a particular quantum state, say N copies, firstly a score is defined to measure how accurately the state is estimated. Then a bound for this score is calculate and is shown to be N+1 N+2 , for a finite ensemble. In my work, with estimated state, I have tried to define quantum measurement in a more general fashion.