Temperature Effect on the Operation of Elementary Quantum-Dot Spin Gates   by the Example of the NOT-AND Gate
  The effect of temperature on the operation of the elementary quantum-dot spin gates for single-electron computing is studied theoretically within the framework of the Hubbard model by the example of the NOT-AND gate. The calculated values of the uniform external magnetic field necessary to realize the whole truth table proved to be unreasonably high for the implementation of the NOT-AND logical function even at the liquid helium temperature. This result appears to be common to all spin gates. Thus, finite temperatures seem to be a serious obstacle for the practical realization of ground state calculations in quantum dot spin gates. 
A.V.Krasheninnikov and R.A.Koltsov (Moscow State Engineering Physics   Institute)