Fig. 2: Thermoelectric characterization.
a Scheme of the electric circuit used to quantify the thermoelectric response of the device, with the temperature difference obtained via a Joule heating current flowing through the Co strip. b Voltage measured vs heating current, with the positive voltmeter electrode on Co and negative on Al at B = 10 mT. The thermovoltage is obtained by subtracting the Ohmic contribution using the average \({V}_{{{{{{{{\rm{th}}}}}}}}}=\frac{V(+{I}_{H})+V(-{I}_{H})}{2}\). c Vth measured at ∣IH∣ = 40 μA vs external magnetic field. d Vth measured vs IH for different bath temperatures up to T = 800 mK (top panel) and temperature difference δT = TCo − TAl estimated from model fits to the tunneling spectroscopy, performed at different bath temperatures and heating currents (bottom panel). e Thermovoltage (top) and Seebeck coefficient (S, bottom) vs temperature difference at selected magnetic field values measured at Tbath = 100 mK. Dash-dotted lines represent the fits to the data considering thermoelectricity with (blue) and without (red) rectification effects. f Seebeck coefficient S extracted at different Tbath and IH.
