Exotic quantum phenomena at interfaces revealed by improvement of numerical methods for many-body systems

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K17746
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: The University of Tokyo
• Principal Investigator: Misawa Takahiro 東京大学, 物性研究所, 特任研究員 (10582687)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 強相関電子系 / 高温超伝導 / 量子スピン液体 / 厳密対角化法 / 変分モンテカルロ法

Outline of Final Research Achievements

We have developed numerical methods that can accurately treat the strongly correlated electron systems. By using the developed methods, we analyzed the superconductivity at the interfaces of the cuprates. As a result, we find that the amplitudes of the superconductivity are pinned at the optimal value in the bulk system. We also show that this mechanism is universal and does not depend on details of models. This results indicates that the interfaces is an ideal to stabilize and optimize the superconductivity without fine tuning of the carrier densities. We also release the open-source software packages mVMC and HΦ, which implement the developed numerical methods.

Free Research Field

物性理論

Academic Significance and Societal Importance of the Research Achievements

高温超伝導などの興味深い現象の舞台となっている強相関電子系を高精度に取り扱える汎用的な数値計算手法の開発を行った。開発した計算手法を用いて、銅酸化物界面での高特性高温超伝導の発現機構、量子スピン液体の有限温度物性などの解析を行った。これらの研究成果は今後の新高温超伝導体・新量子スピン液体の開発につながると期待できる。また、開発した計算手法をオープンソースソフトウェアとして公開を行い、ソフトウェアに関する講習会を開催することで、計算手法の普及活動を行った。