Hybrid quantum systems based on collective excitation in solid emerging from spontaneously symmetry breaking

2018 Fiscal Year Final Research Report

• Project/Area Number: 26220601
• Research Category: Grant-in-Aid for Scientific Research (S)
• Allocation Type: Single-year Grants
• Research Field: Nanostructural physics
• Research Institution: The University of Tokyo
• Principal Investigator: NAKAMURA Yasunobu 東京大学, 先端科学技術研究センター, 教授 (90524083)
• Research Collaborator: ISHIKAWA Toyofumi ; NOGUCHI Atsushi ; GLOPPE Arnaud ; LACHANCE-QUIRION Dany ; INOMATA Kunihiro ; LIN Zhirong ; YAMAMOTO Tsuyoshi ; HIDAKA Mutsuo ; OLIVER William
• Project Period (FY): 2014-05-30 – 2019-03-31
• Keywords: 量子ハイブリッド系 / 超伝導量子ビット / 量子情報 / 量子計測 / ナノメカニクス / マグノニクス

Outline of Final Research Achievements

We investigated coherent control at the level of single quanta of collective excitation in solid, which emerge in a macroscopic scale as a result of spontaneous symmetry breaking. By using superconducting quantum circuits as a tool, we constructed hybrid quantum systems in which quantum degrees of freedom of other physical systems are coherently controlled. The targets included photons in a propagating microwave mode on a superconducting circuit, magnons as quanta of collective spin excitations in a ferromagnetic crystal, and phonons as quanta of collective motions of atoms in nanomechanical devices. We developed a number of techniques to generate and observe nonclassical states, such as squeezed states, Fock states and entangled states, in those hybrid systems.

Free Research Field

量子情報科学

Academic Significance and Societal Importance of the Research Achievements

固体素子中の様々な自由度を量子力学的に制御・観測する手法を開発することにより、固体中の集団励起モードの素励起を直接調べることを可能にするとともに、量子技術の適用領域を拡大し量子情報や量子計測応用への可能性を切り拓いた。