Quantum Tunneling of Magnetization

Thermal fluctuations of fine magnetic particles

“…Above 100 K, the frequency strongly decreases and vanishes at about 250 K. The line width Γ takes a value of about 0.02 meV; it slightly decreases with rising temperature [4]. As for the integrated weight I, the observed temperature dependence is well described by (16), with E B ≈ 250 K.…”

“…. 10 4 , where SA/k B is of the order of 0.1 K. The long-time relaxation behavior of Mn 12 O 12 has been successfully described in terms of (2) with S = 10 and A/k B ≈ 0.6 K [16]. The longitudinal motion involves the barrier E B = S 2 A as activation energy.…”

Multi-step shot noise spectrum induced by a local large spin

“…Single molecular magnets (SMMs), characterized by a local large spin and magnetic anisotropy, have attracted much attention in the last two decades for showing the macroscopic quantum coherence [1][2][3][4] and macroscopic quantum tunneling. [5][6][7][8][9][10] Since Heersche et al [11] were able to trap an SMM in a typical field transistor geometry, great efforts have been devoted to measuring electronic transport through an SMM, which has a potential application for magnetic devices and quantum computation.…”

Magnetic quantum coherence effect in Ni4molecular transistors

“…Recent experiments have pointed out the importance of the interference between spin tunneling paths in molecules. For instance, measurements of the magnetization in bulk Fe 8 have observed oscillations in the tunnel splitting Δ s,−s between states S z = s and −s as a function of a transverse magnetic field at temperatures between 0.05 K and 0.7 K (see [13,14]). This effect can be explained by the interference between Berry phases associated to spin tunneling path of opposite windings [15][16][17][18][19].…”