Abstract
Microscopic mechanisms of the externally controlled reversible thermoelectric effect through the carbon tube junction (NJ) are examined theoretically. The theory interprets earlier experiments in terms of ballistic motion the phase-correlated electrons (e) and holes (h) along the tube section 
. We find that the direction and magnitude of the heat flow critically depend on the gate voltage VG and on the source-drain voltage VSD, both. The voltages adjust the electron energy ε to match the quantized state and van Hove singularities inside 
. Potential applications of the reversible Peltier effect are discussed.