论文标题
确切的基地状态和域壁
Exact Ground States and Domain Walls in One Dimensional Chiral Magnets
论文作者
论文摘要
我们准确地确定了一个空间尺寸中手性磁体的相结构，并与dzyaloshinskii-moriya（dm）相互作用（DM）相互作用，并且潜力是磁化矢量的第三部分的函数，$ n_3 $，$ n_3 $，带有zeeman（带有系数$ b $）的Zeeman（与系数$ b $）（与Anisotropy targitife $ a codedration $ a Condifited $ a），$ a codfitic $ a $ a $ a $ a $ a $ a $ a $ a usefity $ a covedration $ a coved $ a usefience $ a coved $ a。 \ vert b \ vert $。对于大量的潜在参数$ a $和$ b $，该系统位于铁磁阶段之一中，而小值则处于螺旋阶段。在螺旋阶段，我们找到了螺旋溶液的连续性，它们是具有不同时期的一维调制溶液。基态被确定为平均能量最低的螺旋溶液。随着相边界的临近，最低能量螺旋溶液的周期会发散，并且螺旋溶液成为边界处零能量的域壁溶液。域壁溶液的能量在同质相区域为正，但在螺旋相区域为负，表明同质（铁磁）状态的不稳定。螺旋和均质阶段之间的相变顺序以及两极分化（$ n_3 = \ pm 1 $）和canted（$ n_3 \ not = \ pm 1 $）的铁磁性相位是第二阶。
We determine exactly the phase structure of a chiral magnet in one spatial dimension with the Dzyaloshinskii-Moriya (DM) interaction and a potential that is a function of the third component of the magnetization vector, $n_3$, with a Zeeman (linear with the coefficient $B$) term and an anisotropy (quadratic with the coefficient $A$) term, constrained so that $2A\leq \vert B\vert$. For large values of potential parameters $A$ and $B$, the system is in one of the ferromagnetic phases, whereas it is in the spiral phase for small values. In the spiral phase we find a continuum of spiral solutions, which are one-dimensionally modulated solutions with various periods. The ground state is determined as the spiral solution with the lowest average energy density. As the phase boundary approaches, the period of the lowest energy spiral solution diverges, and the spiral solutions become domain wall solutions with zero energy at the boundary. The energy of the domain wall solutions is positive in the homogeneous phase region, but is negative in the spiral phase region, signaling the instability of the homogeneous (ferromagnetic) state. The order of the phase transition between spiral and homogeneous phases and between polarized ($n_3=\pm 1$) and canted ($n_3\not=\pm 1$) ferromagnetic phases is found to be second order.
