You can force heat to turn a corner inside a crystal using magnets—even though that crystal shouldn't be magnetic at all.
April 3, 2026
Original Paper
Phonon Thermal Hall Effect in quartz and its absence in silica
arXiv · 2604.01908
The Takeaway
Normally, magnets only affect electricity, not heat flowing through an insulator. This study proves that the orderly structure of a crystal like quartz can force heat to flow sideways, a discovery that could lead to new ways of managing temperature in electronics.
From the abstract
The observation of a misalignment between the applied heat flux and the measured temperature gradient in insulating solids induced by magnetic field has become a subject of experimental investigation, theoretical speculation, and unsettled controversy. To identify the origin of this phonon thermal Hall effect, we performed a comparative study of longitudinal and transverse heat transport in crystalline (quartz) and vitreous (silica) SiO$_2$ using identical experimental set-ups and thermometers.