Mesoscopic Quadratic Quantum Measurements
Wenjin Mao, D. V. Averin, Rusko Ruskov, Alexander N. Korotkov · Physical Review Letters · 2004
We develop a theory of quadratic quantum measurements by a mesoscopic detector. It is shown that the quadratic measurements should have nontrivial quantum information properties, providing, for instance, a simple way of entangling two noninteracting qubits. We also calculate the output spectrum of a detector with both linear and quadratic response, continuously monitoring two qubits.