室温固体材料で世界最高水準の核スピン偏極率61%を達成～次世代量子技術への応用に期待～

2026-01-16 理化学研究所,埼玉大学,東京大学,東北大学

トリプレットDNP法を用いた水素（¹H）核スピン偏極率の向上

＜関連情報＞

• https://www.riken.jp/press/2026/20260116_2/index.html
• https://www.sciencedirect.com/science/article/abs/pii/S0009261425007493

三重項動的核分極による室温での60%以上の1H分極 1H polarization above 60 % at room temperature by triplet dynamic nuclear polarization

Kenichiro Tateish, Shuji Otsuka, Akihiro Yamaji, Shunsuke Kurosawa, Tomohiro Uesaka
Chemical Physics Letters  Available online: 15 December 2025
DOI:https://doi.org/10.1016/j.cplett.2025.142606

Highlights

• ¹H polarization of 61 % was achieved by Dynamic Nuclear Polarization using photoexcited triplet electrons (Triplet-DNP) at room temperature and in 0.64 T.
• A single crystal of dibenz[a,h]anthracene doped with 0.05 mol% pentacene-d₁₄ has a long spin-lattice relaxation time (T₁) exceeding 2 h at room temperature.
• The potential applications of nuclear ordering and radiation-tolerant polarized target were discussed.

Abstract

We achieved 61 % ¹H polarization at room temperature and in 0.64 T via Dynamic Nuclear Polarization using photoexcited triplet electrons (Triplet-DNP). Dibenz[a, h]anthracene was introduced as a new host for pentacene-d₁₄, providing a long spin-lattice relaxation time (T₁) exceeding 2 h. Single crystals doped with 0.05 mol% pentacene-d₁₄ were grown by the Bridgman method and cut to ∼1 mg for experiments. The ¹H polarization buildup and relaxation measurements indicated that paramagnetic relaxation dominates over spin-lattice relaxation. Finally, potential applications of room-temperature hyperpolarization, i.e., nuclear ordering and radiation-tolerant polarized targets, were discussed.