Physics – Condensed Matter – Mesoscale and Nanoscale Physics
Scientific paper
2011-10-11
New Journal of Physics, 14 015008 (2012)
Physics
Condensed Matter
Mesoscale and Nanoscale Physics
7 pages, 9 figures
Scientific paper
10.1088/1367-2630/14/1/015008
We investigate the thermodynamics of artificial square spin ice systems assuming only dipolar interactions among the islands that compose the array. The emphasis is given on the effects of the temperature on the elementary excitations (magnetic monopoles and their Dirac strings). By using Monte Carlo techniques we calculate the specific heat, the density of poles and their average separation as functions of temperature. The specific heat and average separation between monopoles and antimonopoles exhibit a sharp peak and a local maximum, respectively, at the same temperature, $T_{p}\approx 7.2D/k_{B}$ (here, $D$ is the strength of the dipolar interaction and $k_{B}$ is the Boltzmann constant). As the lattice size is increased, the amplitude of these features also increases but very slowly. Really, the specific heat and the maximum in the average separation $d_{max}$ between oppositely charged monopoles increase logarithmically with the system size, indicating that completely isolated charges could be found only at the thermodynamic limit. In general, the results obtained here suggest that, for temperatures $T \geq T_{p}$, these systems may exhibit a phase with separated monopoles, although the quantity $d_{max}$ should not be larger than a few lattice spacings for viable artificial materials.
Mol Lucas A. S.
Moura-Melo Winder A.
Nascimento Fábio S.
Pereira Afranio Rodrigues
Silva R. C.
No associations
LandOfFree
Thermodynamics of elementary excitations in artificial magnetic square ice does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Thermodynamics of elementary excitations in artificial magnetic square ice, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermodynamics of elementary excitations in artificial magnetic square ice will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-472317