Workshop on

Quantum Mechanics: Axiomatics of Measurements and connections with Computing and Information Retrieval

  MILOSLAV DUSEK, Palacky University

Miloslav Dusek is associate professor at the Department of Optics of Palacky University in Olomouc, Czech Republic. His research activities and interests cover quantum and coherence optics, quantum entanglement, quantum cryptography, quantum information processing, and quantum measurement.

Miloslav Dusek
Several experimental implementations of phase covariant quantum cloner
aula DOTTORATO - MERCOLEdì 11 ottobre, ore 11.00

Several experimental realizations of optimal symmetric probabilistic phase-covariant 1 -> 2 cloning of qubit states is presented. We demonstrate creation of two copies of any state of a qubit with a fixed latitude on the Poincare sphere (especially of states lying at its equator). The states of qubits are encoded into polarization states of photons generated by spontaneous parametric down-conversion. Our devices are based on two main strategies. One of them is the interference of two photons at a beam splitter with different splitting ratios for horizontal and vertical polarizations. The other use a quantum-state filtering based on polarization dependent losses.

aula DOTTORATO - MERCOLEdì 11 ottobre, ore 14.00
Experimental realization of the encoding of two qubits to one qutrit
  We present an optical scheme for the recently proposed protocol for encoding arbitrary non-entangled states of two qubits into a state of one qutrit. Our experimental realization uses spatial-mode encoding. I.e., each qudit is represented by a single photon propagating in d different optical fibers. The compression of two qubits into one qutrit is realized by an unbalanced beam splitter and a subsequent measurement. After successful encoding of two qubits the receiver could error-free restore any of the two encoded qubit states but not both of them simultaneously.
The principle of experiment is based on the interplay of the second-order and fourth-order interference. Further, we propose certain generalizations of the original protocol.