Quantum tomography

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The quantum tomography is a method for reconstructing a quantum state of a series of measurements. It enables the complete measurement of the quantum state of an object, e.g. B. its density matrix or its position and momentum distribution.

In order to be able to clearly identify the condition, the measurements must be tomographically complete. The entire state vector can only be reconstructed if enough measurements are made on state copies. In this way, the Wigner function for representing a quantum state is determined, the projections of which are experimentally accessible.

Since the measurement changes the quantum state due to the uncertainty relation, quantum tomography reconstructs the probable state before the measurement.

application

Quantum tomography plays a crucial role if you want to generate and manipulate quantum states in a tailor-made manner. This is necessary , for example, in quantum informatics and in the technology of quantum computers .

See also

Individual evidence

  1. Stephan Schiller, Gerd Breitenbach: The measurement of optical quantum states. In: Physics Journal. 55, No. 5, 1999, pp. 39-43, doi : 10.1002 / phbl.19990550509 ( PDF ).