This is because a system at zero temperature exists in its ground state, so that its entropy is determined only by the degeneracy of the ground state. Located at: en./wiki/Third_l.thermodynamics. The third law of thermodynamics states that the entropy of a system at absolute zero is a well-defined constant. License: CC BY-SA: Attribution-ShareAlike Located at: en./wiki/Magnetic_refrigeration. Located at: en./wiki/Entropy.hermodynamics).

Located at: en./wiki/Third_l.thermodynamics. License: CC BY-SA: Attribution-ShareAlikeĬC LICENSED CONTENT, SPECIFIC ATTRIBUTION demagnetization: The process of removing the magnetic field from an object.degeneracy: Two or more different quantum states are said to be degenerate if they are all at the same energy level.The total absence of heat the temperature at which motion of all molecules would cease.

absolute zero: The coldest possible temperature: zero on the Kelvin scale and approximately -273.15☌ and -459.67☏.microstate: The specific detailed microscopic configuration of a system.Right: An infinite number of steps is needed since S(0,X1)= S(0,X2).

Left side: Absolute zero can be reached in a finite number of steps if S(T=0,X1)≠S(T=0, X2). Horizontal lines represent isentropic processes, while vertical lines represent isothermal processes. However, going back to the third law, at T=0 there is no entropy difference, and therefore an infinite number of stepswould be needed for this process (illustrated in ).Ĭan Absolute Zero be Reached?: Temperature-Entropy diagram. )Īssuming an entropy difference at absolute zero, T=0 could be reached in a finite number of steps. The parameter X in this case would be the magnetization of the gas. As an example, one can think of a multistage adiabatic magnetization-demagnetization cycle setup where a magnetic field is switched on and off in a controlled way.

Absolute third law entropy