Exclusion Statistics as a Thermodynamic Resource in Quantum Heat Engines

Abstract

The maximum power extractable from a quantum thermoelectric heat engine operating with free fermion carriers is bounded by the universal Whitney limit, $P_{\text{fermion}}^{\max }\simeq 0.0321{\pi }^2{k}_B^2(T_L-T_R{)}^2/h$. We demonstrate that this bound is not fundamental to quantum heat engines but is instead an artifact of fermionic statistics. Within the nonlinear Landauer-Büttiker framework, a bosonic working medium yields a strictly enhanced universal maximum power, $P_{\text{boson}}^{\max }=(\ln 2{)}^2{k}_B^2(T_L-T_R{)}^2/h$, exceeding the fermionic limit by a factor of $(\ln 2{)}^2/(0.0321{\pi }^2)\approx 1.52$. We propose magnon transport through a ferromagnetic spin chain as an experimentally viable bosonic realization. Incorporating Haldane fractional exclusion statistics with parameter $g$ provides a continuous interpolation between the bosonic ($g=0$) and fermionic ($g=1$) limits, revealing a monotonic enhancement of maximum power for $g<1$ at reduced bias cost. These results establish quantum statistical exclusion as a previously unrecognized and independently tunable thermodynamic resource, opening performance regimes inaccessible to conventional carrier-engineering approaches.

arXiv comment6 pages, 4 figures