Quantum Properties of a Which-Way Detector
  We explore quantum properties of a which-way detector using three versions of an idealized two slit arrangements. Firstly we derive complementarity relations for the detector; secondly we show how the "experiment" may be altered in such a way that using single position measurement on the screen we can obtain quantum erasure. Finally we show how to construct a superposition of "wave" and "particle" components. 
J. S. Oliveira Filho, R. Rossi Jr. and M. C. Nemes
quant-ph