A deterministic thermostat for controlling temperature using all degrees of freedom

Area of Science:

• Computational Physics
• Statistical Mechanics
• Thermodynamics

Background:

• Existing thermostats control either kinetic (e.g., Nose-Hoover) or configurational (e.g., Braga-Travis) degrees of freedom.
• A unified approach using all phase space variables for thermostatting is lacking.

Purpose of the Study:

• To introduce a novel thermostat that employs all phase space variables for temperature control.
• To compare its performance against established kinetic and configurational thermostats.
• To evaluate its efficacy in equilibrium, sudden temperature changes, and non-equilibrium thermal conduction.

Main Methods:

• Derivation of the new thermostat using the extended system method, as a special case of Kusnezov et al. equations.
• Comparative performance analysis against Nose-Hoover and Braga-Travis thermostats.
• Testing under equilibrium, sudden thermal shocks, and steady-state thermal conduction.

Main Results:

• All tested thermostats perform comparably in systems at thermal equilibrium.
• The proposed thermostat demonstrates superior performance in thermal conduction simulations.
• A consistent temperature profile was achieved across the conduction length using the new thermostat.

Conclusions:

• The novel phase-space thermostat provides accurate temperature control, particularly in non-equilibrium scenarios.
• Its ability to generate consistent temperature profiles makes it ideal for thermal conduction studies.
• The thermostat is expected to be valuable for a range of non-equilibrium simulations.