Temperature and magnetic field dependent <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>g</mml:mi></mml:math>-factors in electron spin resonance spectroscopy

We propose that phonons coupled to electrons play an important role in both the fundamental phenomenology of electron spin resonance as well as the interpretation of such measurements. By including spin-dependent electron-phonon interactions originating from spin-orbit coupling, we demonstrate that the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mn>g</a:mn></a:math>-f actor acquires emergent temperature dependencies that are in excellent agreement with experimental observations. Moreover, we predict that at low temperatures, the <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mi>g</b:mi></b:math>-factor will exhibit a nontrivial dependence on the magnetic field, indicating a dynamic property that has not been previously considered in electron-phonon systems. We further predict the influence of phonons to be negligible at very low and very high temperatures, with the former requiring experimental verification.