Efficient Schemes for Reducing Imperfect Collective Decoherences

We propose schemes that are efficient when each pair of qubits undergoes some imperfect collective decoherence with different baths. In the proposed scheme, each pair of qubits is first encoded in a decoherence-free subspace composed of two qubits. Leakage out of the encoding space generated by the imperfection is reduced by the quantum Zeno effect. Phase errors in the encoded bits generated by the imperfection are reduced by concatenation of the decoherence-free subspace with either a three-qubit quantum error correcting code that corrects only phase errors or a two-qubit quantum error detecting code that detects only phase errors, connected with the quantum Zeno effect again.Comment: no correction, 3 pages, RevTe

A precise definition of the Standard Model

We declare that we are living in the quantum 4-dimensional Minkowski space-time with the force-fields gauge-group structure $SU_c(3) \times SU_L(2) \times U(1) \times SU_f(3)$ built-in from the very beginning. From this overall background, we see the lepton world, which has the symmetry characterized by $SU_L(2) \times U(1) \times SU_f(3)$ - the lepton world is also called "the atomic world". From the overall background, we also see the quark world, which experiences the well-known $(123)$ symmetry, i.e., $SU_c(3) \times SU_L((2) \times U(1)$. The quark world is also called "the nuclear world". The $3^\circ\,K$ cosmic microwave background (CMB) in our Universe provides the evidence of that "the force-fields gauge-group structure was built-in from the very beginning". The CMB is almost uniform, to the level of one part in $10^5$, reflecting the massless of the photons. The lepton world is dimensionless in the 4-dimensional Minkowski space-time. That is, all couplings are dimensionless. The quark world is also dimensionless in the 4-dimensional Minkowski space-time. Apart from the "ignition" term, the gauge and Higgs sector, i.e., the overall background, is also dimensionless. Thus, apart the "ignition" term, our world as a whole is dimensionless in the 4-dimensional Minkowski space-time - that is, it is the characteristic of the quantum 4-dimensional Minkowski space-time.Comment: 1 figure. arXiv admin note: substantial text overlap with arXiv:1301.646