Conceptional proposal of a microwave-only quantum magnetic head by phase-induced tunneling magnetoresistance effects and of a 3-dimensional multilayer platter

Tunneling magnetoresistance effects result in a high-performance magnetic head, enabling a high magnetic domain density in a platter. This conventional method of using magnetic flux to read or write is close to the magnetic domain density limit. Herein, we propose a conceptional method for developing a magnetic head by controlling phase-induced tunneling magnetoresistance effects. The developed magnetic head can be read out in units of 1 qubit. However, because recording data per BEC qubit is difficult due to thermal fluctuations, we evaluated the robustness of the method and concluded that it is robust to bit flips. Our method does not use a magnetic field for reading or writing, further suggesting that one may use a microwave instead. This is a distinguishing feature, allowing further integration of the magnetic domain density in a platter.