Quantum channel

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A quantum channel is a transmission channel , the quantum information can transmit. Information transfer with or without quantum storage comes into question. An example of quantum information is the spin of a photon (essentially the polarization state ); this enables encrypted or tap-proof information transmission ( quantum cryptography ) , for example .

A quantum channel is mathematically described by a so-called super operator (i.e. an operator that acts on operators) with certain properties. This super operator acts on the density operator , which describes the quantum state on the sender side, and thus indicates the transmission to the receiver side.

literature

  • Dennis Kretschmann and Reinhard F. Werner: Quantum Channels with Memory . In: Phys. Rev. A . 72, 2005. ( online access )