Manipulation of the quantum tunneling of nanomagnets by using time-dependent high magnetic fields
Manipulation of the quantum tunneling of nanomagnets by using time-dependent high magnetic fields
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DOI：
10.1016/j.jmmm.2006.10.616
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发表时间：
2007-03
影响因子：
2.7
通讯作者：
H. Nojiri;Kwang-Yong Choi;N. Kitamura
中科院分区：
文献类型：
--
作者：
H. Nojiri;Kwang-Yong Choi;N. Kitamura
研究了玻璃基质中S=12Cu2+离子磁化强度的量子隧道效应。利用快速扫描磁场实现了绝热条件。即使在偶极耦合可以忽略的稀疏极限下，也能观察到禁止的零场量子隧穿。隧道隙与掺杂浓度无关，其值为20mK。作为这种小隧道带隙的起源，考虑了与在位核自旋(i=32)的超精细耦合。结果表明，在这个S=12，i=32的耦合系统中，由于总自旋是整数，所以隧道效应是允许的。
Quantum tunneling of magnetization of S=12Cu2+ions doped in glass matrix has been investigated. An adiabatic condition has been achieved by using a fast sweeping magnetic field. The forbidden zero field quantum tunneling is observed even in the dilute limit, where the dipolar coupling is negligible. The tunneling gap is independent of the doping concentration and the value is evaluated to be 20mK. As the origin of this small tunneling gap, the hyperfine coupling with the on-site nuclear spin (I=32) is considered. It is found that the tunneling is allowed because the total spin is integer in this coupled system of S=12 and I=32.