PT-Symmetry Enabled Spintronic Thermal Diodes and Logic Gates

Devices for performing computation and logic operations with low-energy consumption are of key importance for environmentally friendly data processing and information technology. Here, a design for magnetic elements that use excess heat to perform logic operations is presented. The basic information channel is coupled non-conductive magnetic stripes with a normal metal spacer. The thermal information signal is embodied in magnetic excitations and it can be transported, locally enhanced, and controllably steered by virtue of charge current pulses in the spacer. Functionality of essential thermal logic gates is demonstrated by material-specific simulations. The operation principle takes advantage of the special material architecture with a balanced gain/loss mechanism for magnetic excitation which renders the circuit parity-time symmetric with exceptional points tunable by the current strength in the spacer. Heat flow at these points can be enhanced, be non-reciprocal, or may oscillate between the information channels enabling controlled thermal diode and thermal gate operations. The findings point to a new route for exploiting heat for useful work on the nanoscale. Information signals can be encoded as thermal spin wave excitations (or magnons) that can be transported, locally enhanced, and controllably steered between two magnetic stripes (or magnonic waveguides) by virtue of charge current pulses in a platinum spacer. Nonlinearity due to non-Hermitian degeneracy and protected by parity-time symmetry enables magnonic thermal diode and thermal logic-gate operations with high fidelity.image

Automated summary

A design for magnetic elements that use excess heat to perform logic operations is presented, allowing for thermal diode and thermal gate operations.