2016 Fiscal Year Research-status Report
| Project/Area Number |
26400340
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| Research Institution | Okinawa Institute of Science and Technology Graduate University |
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Principal Investigator |
コンスタンチノフ デニス 沖縄科学技術大学院大学, 量子ダイナミクスユニット, 准教授 (50462685)
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| Project Period (FY) |
2014-04-01 – 2018-03-31
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| Keywords | nonlinear NMR / BEC of magnons |
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| Outline of Annual Research Achievements |
During FY2016, we continued investigation of possibility of the Bose-Einstein Condensation of non-equilibrium magnons in coupled electron-nuclear spin systems. In particular, we concentrated on the study of nonlinear nuclear resonance in an easy-plane antiferromagnetic MnCO3 sample. The purpose of FY2016 work was to establish connection between nonlinear magnetic properties of MnCO3 crystalline material and superfluid He3.
During FY2016, we carried out extensive experimental study of nonlinear NMR in the MnCO3 sample using the experimental setup which we built and tested during FY2014-2015. We also carried out extensive theoretical analysis using a theory developed in collaboration with theoreticians from Ural Federal University in Russia.
The main achievement of FY2016 is that we established a clear connection between nonlinear magnetic properties of coupled electron-nuclear spin systems in MnCO3 crystalline material and superfluid He3. In particular, we have established that the NMR and nuclear relaxation in both systems are governed by the Landau-Lifshitz-Gilbert mechanism rather than the conventional Bloch mechanism. This provide a necessary prerequisite for the mechanism of BEC of nonequilibrium magnons in both systems.
These finding are published in arXiv. The manuscript is currently under review in the Physical review B.
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| Current Status of Research Progress |
Current Status of Research Progress
3: Progress in research has been slightly delayed.
Reason
While in FY2016 we achieved a great advance in our understanding of nonlinear NMR in coupled electron-nuclear spin systems in crystailline materials, as well as show necessary conditions for existence of BEC of non-equilibrium magnons in these systems, we still need to unequivocally demonstrate the formation of BEC. According to the initially proposed plan for this Kakenhi project, an unequivocal prove of BEC would be the demonstration of the formation of coherent state of non-equlibrium magnon system by incoherent RF pumping.
Currently, we have most of the necessary experimental tools to work on the final goal of this project, that is demonstration of formation of BEC of magnons and spin superfluidity in coupled electron-nuclear spin systems in slid materials. This will comprise our nearest future work.
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| Strategy for Future Research Activity |
In FY2017, we plan to work in two main directions.
1. Having shown the necessary prerequisites for the formation of BEC in MnCO3 sample, we plan to investigate the possibility for formation of BEC on non-equilibrium magnons in this system by employing noisy incoherent RF pumping of magnons. We will use the existing setup which was used for our nonlinear NMR studies of MnCO3 in FY2016.
2. We will continue our experimental study of the strong coupling of magnon system to the RF resonator and investigate the possibility for using MnCO3 material for spin-based quantum memory applications.
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| Causes of Carryover |
Since we have concentrated on carrying out the experimental measurements and theoretical work, we did not have much expenses on materials and instruments.
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| Expenditure Plan for Carryover Budget |
In accordance to the proposed plan, we are going to modify our experimental setup to include the incoherent RF umping source. The rest of the budget will be used for purchase of necessary instruments and consumables (connectors, cables, etc.) to build the incoherent RF source and incorporate it with the setup.
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