February 12, 2019

# Introduction to the quantum first detection problem

Seminar: Topical Issues of Theoretical Physics

- Time
- February 12, 2019 1:15 PM
- Lecturer
- Eli Barkai (Physics Department Bar-Ilan University Ramat-Gan)

We consider quantum dynamics on a graph, with repeated strong measurements per- formed locally at a fixed time interval τ . For example a particle starting on node χ and measurements performed on another node χ´. From the basic postulates of quantum mechanics the string of measurements yields a sequence no,no,no, ∙∙∙ and finally in the n-th attempt a yes, i.e. the particle is detected. Statistics of the first detection time nτ are investigated, and compared with the corresponding classical first passage problem. Dark states, Zeno physics, a quantum renewal equation, winding number for the first return problem (work of A. Grunbaum et al.), total detection probability, detection time operators and time wave functions are discussed.