Quantum theory of entangled-photon photoemission
Abstract
A quantum theory of two-photon volume photoemission from metals and semiconductors is developed when the incident source of light comprises collinear down-converted entangled-photon pairs with entanglement time Te. Despite the fact that the process involves the absorption of pairs of photons, the entangled-photon photocurrent varies linearly with the incident photon flux density. This is a consequence of the fact that the presence of one photon of an entangled-photon pair signals the presence of the other; it is in sharp contrast with the quadratic dependence of the classical two-photon photocurrent on incident photon flux density. Calculations are carried out for sodium metal (Na) and for K2CsSb, a bialkali-antimonide semiconductor material often used as a cathode in photomultiplier tubes. The photocurrent is found to vary inversely with entanglement time although nonmonotonic behavior emerges over certain ranges of Te. Entangled-photon photoemission may well be useful for enhancing the range of two-photon photoemission spectroscopy and might find particular use in the investigation of surface and image states of various materials.
- Publication:
-
Physical Review B
- Pub Date:
- April 2004
- DOI:
- 10.1103/PhysRevB.69.165317
- Bibcode:
- 2004PhRvB..69p5317L
- Keywords:
-
- 79.60.Bm;
- 42.65.Lm;
- 03.65.-w;
- Clean metal semiconductor and insulator surfaces;
- Parametric down conversion and production of entangled photons;
- Quantum mechanics