Heat switch effect in one-dimensional spin chains

We study heat transport in one-dimensional (1-D) quantum spin systems by the nonequilibrium Green's function method. We show that, in both ferromagnetic and antiferromagnetic systems, the excitation spectrums of the reservoirs and the central spin chain can be tuned to be matched or mismatched by changing the external magnetic field. When the spectrums are matched, heat current through the system is large; however if the spectrums are mismatched, heat current becomes much smaller. Through tuning the magnetic field, the system can thus act as a heat switch, and we discuss the condition for the system to exhibit strong switch effect. -- Highlights: → We study heat transport in one-dimensional (1-D) quantum spin systems. → The system can act as a heat switch by tuning the magnetic field. → We discuss the condition for the system to exhibit strong switch effect.