Extended Data Fig. 3: Thermal noise analysis at ν = 2 in the bulk in the high-mobility SPSL structure.
Dissipated power in the floating reservoir is plotted as a function of Tm for different numbers of open arms, N, with one edge mode allowed to flow in each arm (controlled by the surface gates). Dashed curves show the one-parameter fit of α from ΔP(ακ0T2, βT5) for a given β (the value deduced from all the experiments). The apparent total thermal conductance is K = 7.34κ0 at N = 4 instead of K = 4κ0, and K = 5.33κ0 at N = 2 instead of K = 2κ0. The inset shows the dissipated power obtained when subtracting the contributions of a different number of open arms; this cancels the added phonons and bulk contributions, both of which depend only on Tm. The fit line leads to the average thermal conductance per channel gQ = (1.03 ± 0.04)κ0T, which agrees with the expectations. (Errors mentioned here correspond to a confidence level of better than 95%.) This device was not used in the experiments.
