Description

Place: Seminar room, Theoretical Physics

Time: 15:00

TITLE: Introduction to quantum state tomography

SPEAKER: Adam Miranowicz

AFFILIATION: Adam Mickiewicz University,  Poznan,  Poland

ABSTRACT:

Quantum state tomography (QST) is a method of determining an
unknown quantum state (density matrix) in a series of measurements
on multiple copies of the state. QST is an essential tool for the
verification and benchmarking of quantum devices used, e.g., for
quantum state engineering, quantum communication, and quantum
information processing.

I will discuss how to implement a few optimal methods of QST for
(i) polarization states of two photons [1] and (ii) solid-state
systems with a large nuclear spin I = 3/2 in nanometer-scale
semiconductors devices based on a quantum well [2]. I will also
report a recent optical experimental implementation of an optimal
QST [3].

REFERENCES:

[1] A. Miranowicz, K. Bartkiewicz, J. Perina Jr., M. Koashi, N.
Imoto, and F. Nori: Optimal two-qubit tomography based on local
and global measurements: Maximal robustness against errors as
described by condition numbers, Phys. Rev. A 90, 062123 (2014).

[2] A. Miranowicz, S.K. ÷zdemir, J. Bajer, G. Yusa, N. Imoto, Y.
Hirayama, F. Nori: Quantum state tomography of large nuclear spins
in a semiconductor quantum well: Optimal robustness against errors
as quantified by condition numbers, Phys. Rev. B 92, 075312
(2015).

[3] K. Bartkiewicz, A. »ernoch, K. Lemr, A. Miranowicz: Priority
Choice Experimental Two-qubit Tomography: Measuring One by One All
Elements of Density Matrices, e-print arXiv:1506.01317