講　座

磁気共鳴分光
I．NMRの原理

Magnetic Resonance Spectroscopy
I. Basics of NMR

廣明 秀一
Hidekazu HIROAKI

　　核磁気共鳴法 (NMR)は，原子核が強い磁場中に置かれると特定のエネルギーの電磁波を吸収するような性質を持つことを利用した分光法である．現在，NMRは化学における分子構造決定をはじめとして，固体物性研究や，構造生物学，画像診断への応用へと幅広い広がりをみせている．また，核スピンの量子力学的重ね合わせ状態を操作できるという特徴を生かして，量子コンピューティングの装置としても注目されている．

　　Nuclear Magnetic Resonance (NMR) is one of the key methodology of spectroscopy, which is based on the resonation between nuclear spin and radio frequency electric wave under the strong magnetic field. Although NMR began its history as a phenomena of quantum physics, its modern pulse-FT NMR have been widely applied in the area of analytical chemistry, molecular biology, medicine and quantum computing. In this review, the basic theory of NMR is introduced according to the classical magnetization model rather than the view of quantum mechanics. The meaning of the data available from NMR, such as chemical shift, spin coupling, and coupling constant as well as basics of density matrix and product operator formalism is briefly described.