  Detection of moving charge in free space is presented in the framework of
single electron CMOS devices. It opens the perspective for construction of new
type detectors for beam diagnostic in accelerators or for the detection of
solar wind. General phenomenological model of noise acting on position based
qubit implemented in semiconductor quantum dots is given in the framework of
simplistic tight-binding model. Furthermore the effect of accelerator beam on
the system of 2 electrostatically coupled qubits is formulated by tight-binding
equations. The position based qubits of various topologies are described as
quantum detectors of moving electric charge.
  Keywords: tight-binding model, position-based qubit, non-invasive quantum
measurement, quantum decoherence of qubit system, accelerator beam diagnostics,
electrostatic noise, phase rotating gate, roton position-based qubit
