Licentiate Thesis: Dimensions and non-contextuality
by
Johan Ahrens(Fysikum)
→
Europe/Stockholm
FA31
FA31
Description
This thesis is based on the three experiments which are the results of my first three years as a PhD-student. Two experiments touch on non-contextuality.
One other experiment shows a realization of a witness function for classical- and quantum dimensions of sets of states.
A fundamental resource in any communication and computation task is the amount of information that can be transmitted and processed. The classical in-
formation encoded in a set of states is limited by the number of distinguishable states or classical dimension dc of the set. The sets used in quantum communi-
cation and information processing contain states which are neither identical nor distinguishable, and the quantum dimension dq of the set is the dimension of the
Hilbert space spanned by these states. In the thesis we report experimental tests of dimension witnesses designed to eciently determine the minimum dimension
of sets of (three or four) photonic states from the correlations originated from measurements on them, and distinguish between classical and quantum sets of
states. This is done in a device- independent way, that is, without referring to the internal working of the device generating the states.
In the area of non-contextuality we show experimental violation of the simplest inequality where there is a discrepancy between classical and quantum mechanics. Further we also show experimental violation of the simplest non-contextuality inequality which can be violated by qutrits.
