Open n-Qubit System as a Quantum Computer with Four-Valued Logic
Abstract
In this paper we generalize the usual model of quantum computer to a model in which the state is an operator of density matrix and the gates are general superoperators (quantum operations), not necessarily unitary. A mixed state (operator of density matrix) of n two-level quantum system (open or closed n-qubit system) is considered as an element of $4^{n}$-dimensional operator Hilbert space (Liouville space). It allows to use quantum computer (circuit) model with 4-valued logic. The gates of this model are general superoperators which act on n-ququats state. Ququat is quantum state in a 4-dimensional (operator) Hilbert space. Unitary two-valued logic gates and quantum operations for n-qubit open system are considered as four-valued logic gates acting on n-ququats. We discuss properties of quantum 4-valued logic gates. In the paper we study universality for quantum four-valued logic gates.
- Publication:
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arXiv e-prints
- Pub Date:
- December 2001
- DOI:
- 10.48550/arXiv.quant-ph/0112023
- arXiv:
- arXiv:quant-ph/0112023
- Bibcode:
- 2001quant.ph.12023T
- Keywords:
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- Quantum Physics
- E-Print:
- 25 pages, LaTeX