Hybridization of Acoustic Resonance with Magnon and photON in YIG

通信和量子信息领域的新发展要求为后CMOS技术引入新材料，这些新材料提供新的超低功耗微波功能，同时保持与集成和纳米图形的兼容。在这方面，具有改善微波或光学器件性能的良好记录的磁性石榴石是主要的候选者。到目前为止，YIG薄膜的高质量外延生长只能在GGG衬底上实现，这阻碍了YIG薄膜在集成溶液中的发展。然而，GGG必须被认为是声子和光子特性的匹配材料，因此提供了能量泄漏路径，从而阻止了它们的微波能量被限制在唯一的YIG层内。为了解决这个问题，哈勒的G.Schmidt小组开发了一种新的工艺，可以制造出具有高磁振子寿命的微米级自支撑YIG梁，从而主要避免了通过衬底的能量泄漏。这些新产品有可能成为以GHz频率运行的高保真前端电信组件的游戏规则改变者。此外，它们还可以为同样工作在GHz频率的遥远量子比特之间的量子信息交换提供新的工具。HARMONY将通过提供一条可行的发展道路，为在芯片上集成光子-磁振子之间的相干和有效的信息相互转换提供一条可行的发展道路，从而开启一项技术突破。它建立在磁性石榴石内部的三方杂交过程之上，该过程采用了日益精细的嵌套共振。Harmonity专注于制造悬浮YIG光束，通过以下目标消除技术障碍：i)通过3个腔的共同调谐，提供一种通过磁弹性效应激发GHz声子的有效方案；ii)通过与衬底隔离的超低损耗材料提高能源效率，以获得最高的精确度；iii)在集成的芯片设备中实现这一点。Harmonity项目的目标是在3年内评估这些悬浮石榴石结构作为微波换能器的性能。该项目被设计为斯宾特克、内尔和哈雷三人小组之间的合作。它们相互补充的记录的协同作用将使我们能够实现这些雄心勃勃的目标。虽然磁子与微波光子的低温耦合将主要在德国进行，但磁子与声子的耦合将在法国进行。微图案化和YIG沉积是唯一位于Halle的位置，而微磁模拟和谐振器设计以及在室温下通过FMR显微镜对所有结构的表征都是在Spintec完成的，并与Néel振动模式的光学机械调查相匹配。

New developments in telecommunication and quantum information necessitate the introduction of new materials for post CMOS technologies that offer new ultra low dissipation microwave functionalities, while remaining compatible with integration and nano-patterning. In this respect, magnetic garnets with a well-established track record of improving the performance of microwave or optical devices are prime candidates. So far the development of yttrium iron garnet (YIG) thin films for integrated solutions was hampered by the fact that high quality epitaxial growth could only be achieved on gadolinium gallium garnet (GGG) substrates. GGG, however, must be considered as a matched material for both the phonon and photon character, which thus offers an energy leakage path and as a consequence prohibits the confinement of their microwave energy within the sole YIG layer. To overcome this problem, a new process developed by the group of G. Schmidt in Halle has allowed to fabricate free standing micron-size YIG beams with high magnon life time, hereby mainly avoiding the energy leakage through the substrate. These new objects have the potential to become game-changers for high-fidelity front-end telecom components operating at GHz frequencies. Furthermore, they can provide new tools for quantum information exchange between distant qbits also operating at GHz frequencies.HARMONY will initiate a technological breakthrough by providing a viable development path for integrating the coherent and efficient interconversion of information between photon-magnon-phonon on a chip. It builds on the tripartite hybridization process inside magnetic garnets that employs nested resonances of increasing finesse. HARMONY focuses on the fabrication of suspended YIG beams to remove technological road-blocks by the following goals: i) provide an efficient scheme to excite GHz phonons by magneto-elastic effects through the co-tuning of 3 cavities; ii) improve the energy efficiency with an ultra-low loss material that is isolated from the substrate for the highest finesse and iii) implement this in an integrated on-chip device.The objective of the project HARMONY will be to evaluate within a 3 years period, how these suspended garnet structures perform as microwave transducers. The project is designed as a collaboration between the group of Spintec, Néel and Halle. The Synergy of their complementary track records will allow us to realize these ambitious goals. While coupling of magnons to microwave photons at low temperature will mainly be performed in Germany, the coupling of magnons to phonons will be performed in France. The micropatterning and YIG deposition is uniquely located in Halle while micromagnetic simulations and resonator design as well as characterization of all structures by FMR microscopy at room temperature is done at Spintec, matched by opto-mechanical surveys of the vibration pattern at Néel.