Fully tunable, non-invasive thermal biasing of gated nanostructures suitable for low-temperature studies

There is much recent interest in the thermoelectric (TE) characterization of single nanostructures at low temperatures, because such measurements yield information that is complementary to traditional conductance measurements, and because they may lead to novel paradigms for TE energy conversion. However, previously reported techniques for thermal biasing of nanostructures are difficult to use at low temperatures because of unintended global device heating, the lack of ability to continuously tune the thermal bias, or limited compatibility with gating techniques. By placing a heater directly on top of the electrical contact to a single InAs nanowire, we demonstrate fully tunable thermal biases of up to several tens of Kelvin, combined with negligible overall heating of the device, and with full functionality of a back gate, in the temperature range between 4 K and 300 K.