36 citations · 126 across the 26 of their papers we have counts for
6 papers · 1 filter
Classical Coding and the Cauchy-Schwarz Inequality
Bas Janssens
In classical coding, a single quantum state is encoded into classical information. Decoding this classical information in order to regain the original quantum state is known to be…
Optimal estimation of qubit states with continuous time measurements
Madalin Guta, Bas Janssens, Jonas Kahn
We propose an adaptive, two steps strategy, for the estimation of mixed qubit states. We show that the strategy is optimal in a local minimax sense for the trace norm distance as w…
Unifying Decoherence and the Heisenberg Principle
Bas Janssens
We exhibit three inequalities involving quantum measurement, all of which are sharp and state independent. The first inequality bounds the performance of joint measurement. The sec…
Information Transfer Implies State Collapse
Bas Janssens, Hans Maassen
We attempt to clarify certain puzzles concerning state collapse and decoherence. In open quantum systems decoherence is shown to be a necessary consequence of the transfer of infor…
Optimal Pointers for Joint Measurement of sigma-x and sigma-z via Homodyne Detection
Bas Janssens, Luc Bouten
We study a model of a two-level system (i.e. a qubit) in interaction with the electromagnetic field. By means of homodyne detection, one field-quadrature is observed continuously i…
Quantum Measurement, a coherent description
Bas Janssens
It is widely known that `collapse of the wave function' on a quantum system A may be brought about by an interaction with another quantum system B. We will prove that this is not j…