Coupled Ito equations of continuous quantum state measurement and estimation

Lajos Diósi*, Thomas Konrad, Artur Scherer, Jürgen Audretsch

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


We discuss a nonlinear stochastic master equation that governs the time evolution of the estimated quantum state. Its differential evolution corresponds to the infinitesimal updates that depend on the time-continuous measurement of the true quantum state. The new stochastic master equation couples to the two standard stochastic differential equations of time-continuous quantum measurement. For the first time, we can prove that the calculated estimate almost always converges to the true state, also at low-efficiency measurements. We show that our single-state theory can be adapted to weak continuous ensemble measurements as well.

Original languageEnglish
Article numberL01
Pages (from-to)L575-L581
Number of pages7
JournalJournal of Physics A: Mathematical and General
Issue number40
Publication statusPublished - 6 Oct 2006
Externally publishedYes


Dive into the research topics of 'Coupled Ito equations of continuous quantum state measurement and estimation'. Together they form a unique fingerprint.

Cite this