[22a-A205-1~11] 10.2 スピン基盤技術・萌芽的デバイス技術

▲ [22a-A205-10] Magnonic cross-bar interference-based reconfigurable logic gate

〇(DC)shamim sarker¹、Lihao Yao¹、Kaijie Ma¹、Hiroyasu Yamahara¹、Siyi Tang¹、Kenyu Terao¹、Zhiqiang Liao¹、Munetoshi Seki¹、Hitoshi Tabata¹ (1.Tokyo Univ)

キーワード：Spin wave, Interference, XOR/XNOR

In this study, we demonstrate a reconfigurable XNOR/XOR logic gate based on the interference of the two different types of spin waves (i.e., magnetostatic surface spin waves (MSSWs) and backward volume magnetostatic spin waves (BVMSWs)) propagating along the orthogonal arms. The reconfigurability has been addressed by the current induced temperature rise and thermal gradient. Using the PLD technique, we grew a 90-nm-thick Y₃Fe₅O₁₂ (YIG) thin film on a Gd₃Ga₅O₁₂ substrate. In the next step, laser-lithography and wet etching with hot phosphoric acid at 140 ⁰C to fabricate a cross structure. Several alignment exposures were performed to fabricate Pt heater and contact electrodes along with the coplanar waveguides (CPWs), shown in Figure 1(c). Two antennas (i.e., identified as CPW1 and CPW3) were used for SWs excitation, while the CPW2 was used for SWs detection. MSSW from CPW3 and BVMSW from CPW1 interact at the cross junction CPW2 and is detected thereafter. The phase of BVMSW SW is fixed, whereas the phase of the MSSW SWs was tuned from 0⁰ to 360⁰ to make them interfere constructively and destructively. Figure 1(b)) depicts the interference pattern of the magnetic cross with the application of J_dc =0, 4.5, 6.0, 7.5, 9.0, 9.7, 10.5 GAm^-2, represented by the corresponding colors. The change in the interference pattern is caused by the cross interaction of the BVMSW and MSSWdue to the temperature change, as depicted in Figure 1(c). The wavelength shift due to temperature results in the interference pattern shift resulting in the reconfigurability of the logic gate as mentioned in Table-I and Table-II based on the black and green curves, respectively.