Dephasing of quantum tunnelling in molecular nanomagnets

Dephasing mechanism of quantum tunnelling in molecular magnets has been studied by means of the spin-coherent-state path integral in a mean field approximation. It is found that the fluctuating uncompensated transverse field from the dipolar-dipolar interaction between molecular magnets contributes a random phase to the quantum interference phase. The resulting transition rate is determined by the average tunnel splitting over the random phase. Such a dephasing process leads to the suppression of quenching due to the quantum phase interference, and to the steps due to odd resonances in hysteresis loop survived, which is in good agreement with experimental observations in molecular nanomagnets Fe₈ and Mnsingle molecule magnet, quantum tunnelling, dephasingProject supported by the National Natural Science Foundation of China (Grant No 10575045).7550X, 7340E, 7535CDephasing mechanism of quantum tunnelling in molecular magnets has been studied by means of the spin-coherent-state path integral in a mean field approximation. It is found that the fluctuating uncompensated transverse field from the dipolar-dipolar interaction between molecular magnets contributes a random phase to the quantum interference phase. The resulting transition rate is determined by the average tunnel splitting over the random phase. Such a dephasing process leads to the suppression of quenching due to the quantum phase interference, and to the steps due to odd resonances in hysteresis loop survived, which is in good agreement with experimental observations in molecular nanomagnets Fe₈ and Mnsingle molecule magnet, quantum tunnelling, dephasingProject supported by the National Natural Science Foundation of China (Grant No 10575045).7550X, 7340E, 7535CDephasing mechanism of quantum tunnelling in molecular magnets has been studied by means of the spin-coherent-state path integral in a mean field approximation. It is found that the fluctuating uncompensated transverse field from the dipolar-dipolar interaction between molecular magnets contributes a random phase to the quantum interference phase. The resulting transition rate is determined by the average tunnel splitting over the random phase. Such a dephasing process leads to the suppression of quenching due to the quantum phase interference, and to the steps due to odd resonances in hysteresis loop survived, which is in good agreement with experimental observations in molecular nanomagnets Fe₈ and Mnsingle molecule magnet, quantum tunnelling, dephasingProject supported by the National Natural Science Foundation of China (Grant No 10575045).7550X, 7340E, 7535CDephasing mechanism of quantum tunnelling in molecular magnets has been studied by means of the spin-coherent-state path integral in a mean field approximation. It is found that the fluctuating uncompensated transverse field from the dipolar-dipolar interaction between molecular magnets contributes a random phase to the quantum interference phase. The resulting transition rate is determined by the average tunnel splitting over the random phase. Such a dephasing process leads to the suppression of quenching due to the quantum phase interference, and to the steps due to odd resonances in hysteresis loop survived, which is in good agreement with experimental observations in molecular nanomagnets Fe₈ and Mnsingle molecule magnet, quantum tunnelling, dephasingProject supported by the National Natural Science Foundation of China (Grant No 10575045).7550X, 7340E, 7535CDephasing mechanism of quantum tunnelling in molecular magnets has been studied by means of the spin-coherent-state path integral in a mean field approximation. It is found that the fluctuating uncompensated transverse field from the dipolar-dipolar interaction between molecular magnets contributes a random phase to the quantum interference phase. The resulting transition rate is determined by the average tunnel splitting over the random phase. Such a dephasing process leads to the suppression of quenching due to the quantum phase interference, and to the steps due to odd resonances in hysteresis loop survived, which is in good agreement with experimental observations in molecular nanomagnets Fe₈ and Mn$_{12}.$