Baiko D A
A F Ioffe Physical-Technical Institute, St. Petersburg, Russian Federation.
Phys Rev E Stat Nonlin Soft Matter Phys. 2009 Oct;80(4 Pt 2):046405. doi: 10.1103/PhysRevE.80.046405. Epub 2009 Oct 22.
The body-centered-cubic Coulomb crystal of ions in the presence of a uniform magnetic field is studied using the rigid electron background approximation. The phonon mode spectra are calculated for a wide range of magnetic-field strengths and for several orientations of the field in the crystal. The phonon spectra are used to calculate the phonon contribution to the crystal energy, entropy, specific heat, Debye-Waller factor of ions, and the rms ion displacements from the lattice nodes for a broad range of densities, temperatures, chemical compositions, and magnetic fields. Strong magnetic field dramatically alters the properties of quantum crystals. The phonon specific heat increases by many orders of magnitude. The ion displacements from their equilibrium positions become strongly anisotropic. The results can be relevant for dusty plasmas, ion plasmas in Penning traps, and especially for the crust of magnetars (neutron stars with superstrong magnetic fields B > or approximately equal 10(14) G ). The effect of the magnetic field on ion displacements in a strongly magnetized neutron star crust can suppress the nuclear reaction rates and make them extremely sensitive to the magnetic-field direction.
利用刚性电子背景近似研究了均匀磁场中离子的体心立方库仑晶体。计算了在很宽的磁场强度范围以及晶体中磁场的几个取向情况下的声子模谱。利用声子谱计算了在很宽的密度、温度、化学成分和磁场范围内，声子对晶体能量、熵、比热、离子德拜 - 瓦勒因子以及离子相对于晶格节点的均方根位移的贡献。强磁场极大地改变了量子晶体的性质。声子比热增加了许多个数量级。离子相对于其平衡位置的位移变得强烈各向异性。这些结果可能与尘埃等离子体、潘宁阱中的离子等离子体相关，尤其与磁星（具有超强磁场(B\geq10^{14})G的中子星）的地壳相关。磁场对强磁化中子星地壳中离子位移的影响可以抑制核反应速率，并使其对磁场方向极其敏感。
