Magnetic field induced modulation of heat transport in CrPS 4 probed by TaIrTe 4 transverse Seebeck thermometry

Understanding and controlling heat flow in low-dimensional magnetic materials is central to thermoelectrics and spin caloritronics. One of the challenges is the absence of sensitive probes of small, field-dependent modulations in thermal transport. Here we demonstrate transverse Seebeck thermometry using exfoliated TaIrTe 4 as a probe of thermal conductivity modulated by an external magnetic field on a van der Waals magnet, CrPS 4. With a temperature gradient oriented at 45 to its principal crystallographic axes, TaIrTe 4 exhibits a transverse thermopower exceeding 200 μV,K-1 for 900 nm wide and 30 μ m long electrodes, enabling precise detection of variations in the local temperature gradients. Exploiting this with CrPS 4 in a nonlocal geometry, we resolve distinct field dependent thermal conductivity changes associated with both the spin-flip and spin-flop magnetic transitions which we attribute to variations in the magnon - phonon coupling in CrPS 4. At 5 K, the transverse Seebeck response is modulated by more than 8 % by an external magnetic field, demonstrating strong magnetic control of heat transport in CrPS 4. This all van der Waals platform offers high sensitivity to modulations of thermal conductivity and a broad adaptability to a wide range of exfoliated magnetic systems.