Projective Ring Line Encompassing Two-Qubits

dc.creatorSaniga, Metod
dc.creatorPlanat, Michel
dc.creatorPracna, Petr
dc.date2006-11-06
dc.date2006-12-28
dc.date.accessioned2026-07-07T09:46:44Z
dc.date.available2026-07-07T09:46:44Z
dc.descriptionThe projective line over the (non-commutative) ring of two-by-two matrices with coefficients in GF(2) is found to fully accommodate the algebra of 15 operators - generalized Pauli matrices - characterizing two-qubit systems. The relevant sub-configuration consists of 15 points each of which is either simultaneously distant or simultaneously neighbor to (any) two given distant points of the line. The operators can be identified with the points in such a one-to-one manner that their commutation relations are exactly reproduced by the underlying geometry of the points, with the ring geometrical notions of neighbor/distant answering, respectively, to the operational ones of commuting/non-commuting. This remarkable configuration can be viewed in two principally different ways accounting, respectively, for the basic 9+6 and 10+5 factorizations of the algebra of the observables. First, as a disjoint union of the projective line over GF(2) x GF(2) (the "Mermin" part) and two lines over GF(4) passing through the two selected points, the latter omitted. Second, as the generalized quadrangle of order two, with its ovoids and/or spreads standing for (maximum) sets of five mutually non-commuting operators and/or groups of five maximally commuting subsets of three operators each. These findings open up rather unexpected vistas for an algebraic geometrical modelling of finite-dimensional quantum systems and give their numerous applications a wholly new perspective.
dc.description8 pages, three tables; Version 2 - a few typos and one discrepancy corrected; Version 3: substantial extension of the paper - two-qubits are generalized quadrangles of order two; Version 4: self-dual picture completed; Version 5: intriguing triality found -- three kinds of geometric hyperplanes within GQ and three distinguished subsets of Pauli operators
dc.identifierhttps://arxiv.org/abs/quant-ph/0611063
dc.identifierhttp://arxiv.org/abs/quant-ph/0611063
dc.identifierTheoretical and Mathematical Physics 155, 3 (2008) 905-913
dc.identifierdoi:10.1007/s11232-008-0076-x
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/163633
dc.subjectQuantum Physics
dc.titleProjective Ring Line Encompassing Two-Qubits
dc.typetext

Files

Collections