Events
QUANTUM HEAT ENGINES AND REFRIGERATORS
00:00 01-05-2007
The unavoidable irreversible loss of power in a heat
engine is found to be of quantum origin. Following thermodynamic
tradition a model quantum heat engine operating in an Otto cycle
is analysed. When the engine deviates from adiabatic conditions
the performance is subject to friction. The origin of this
friction can be traced to the noncommutability of the kinetic and
potential energy of the working medium. The scaling of the cooling
power of a reciprocating quantum refrigerator is sought as a func-
tion of the cold bath temperature. When the working medium Hamil-
tonian contains an uncontrolled internal coupling, the cooling
power vanishes exponentially. If the internal energy gap can be
made to follow the cold bath temperature the cooling power
vanishes at least as T_c^3
engine is found to be of quantum origin. Following thermodynamic
tradition a model quantum heat engine operating in an Otto cycle
is analysed. When the engine deviates from adiabatic conditions
the performance is subject to friction. The origin of this
friction can be traced to the noncommutability of the kinetic and
potential energy of the working medium. The scaling of the cooling
power of a reciprocating quantum refrigerator is sought as a func-
tion of the cold bath temperature. When the working medium Hamil-
tonian contains an uncontrolled internal coupling, the cooling
power vanishes exponentially. If the internal energy gap can be
made to follow the cold bath temperature the cooling power
vanishes at least as T_c^3
