Simultaneous measurement of specific heat and thermal conductivity in pulsed magnetic fields.

We report an experimental setup for simultaneously measuring specific heat and thermal conductivity in feedback-controlled pulsed magnetic fields of 50 ms duration at cryogenic temperatures. A stabilized magnetic field pulse obtained by the feedback control, which dramatically improves the thermal stability of the setup and sample, is used in combination with the flash method to obtain absolute values of thermal properties up to 37.2 T in the 22-16 K temperature range.

Observation of Poiseuille flow of phonons in black phosphorus.

The travel of heat in insulators is commonly pictured as a flow of phonons scattered along their individual trajectory. In rare circumstances, momentum-conserving collision events dominate, and thermal transport becomes hydrodynamic. One of these cases, dubbed the Poiseuille flow of phonons, can occur in a temperature window just below the peak temperature of thermal conductivity.

Colossal Seebeck Coefficient of Hopping Electrons in (TMTSF)_{2} PF_{6}.

We report on a study of the Seebeck coefficient and resistivity in the quasi-one-dimensional conductor (TMTSF)_{2} PF_{6} extended deep into the spin-density-wave state. The metal-insulator transition at T_{SDW}=12  K leads to a reduction in carrier concentration by 7 orders of magnitude. Below 1 K, charge transport displays the behavior known as variable range hopping.