Quantitative quantum erasure

Quantum erasure aims at large fringe visibility in sorted subensembles. Since the achieved visibility depends on the specific sorting scheme, we optimize the sorting procedure under general circumstances. The possible compromises between fringe visibility (wave-typical) and which-alternative knowledge (particle-typical) are governed by a number of inequalities that are quantitative statements about wave-particle duality. Among them is the 'erasure relation', which stares an absolute upper bound on the visibility that a quantum eraser can yield. (C) 2000 Elsevier Science B.V. All rights reserved.