Hannover 2013 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 35: Poster I

Q 35.95: Poster

Tuesday, March 19, 2013, 16:00–18:30, Empore Lichthof

Highly non-classical symmetric states of an N-qubit system — •Dorian Baguette and John Martin — Institut de Physique Nucléaire, Atomique et de Spectroscopie, Université de Liège, Bât. B15, B - 4000 Liège, Belgium

A host of applications of quantum phenomena, such as quantum information processing and quantum-enhanced measurements, rely on the non-classical nature of quantum states[1]. In this work, we study two measures of non-classicality for pure symmetric N-qubit states : Wehrl participation ratio and Wehrl entropy. We focus more particularly on the identification of the most non-classical symmetric states with respect to these measures and on their nice geometrical properties in the Majorana representation[2]. The scaling of these measures with the number of qubits is also investigated. We show that the quest for the most non-classical symmetric states is somehow related to J. J. Thomson's century-old problem of the minimum energy configuration of charges on the surface of a sphere.

[1] C. Anastopoulos, Phys. Rev. D 59, 045001 (1998).

[2] I. Bengtsson & K. Zyczkowski, Geometry of Quantum States, Cambridge University Press (2006).