论文标题
在磁性材料中解锁时间逆转，时空反转和旋转不变
Unlocking of time reversal, space-time inversion and rotation invariants in magnetic materials
论文作者
论文摘要
时间逆转（$ t $）和太空反转是我们宇宙的对称性，以低能限制。基本定理将其相应的量子数与基本粒子的自旋联系起来：$ \ hat {t}^2 =（\ hat {p} \ hat {t}）^2 = -1 $ for half-odd-odd-integer spins spins和$ \ hat {t}^2 =（t}^2 =（t}^2 =（p） Here we show that for elementary excitations in magnetic materials, this "locking" between quantum numbers is lifted: $\hat{T}^2$ and $(\hat{P}\hat{T})^2$ take all four combinations of $+1$ and $-1$ regardless of the value of the spin, where $T$ now represents the composite symmetry of time reversal and lattice translation.解锁的量子数导致这些激发与外部磁场之间的最小耦合形式，从而实现了新型的物理现象，例如“交叉倾向进动”，在拟议的光吸收实验中可间接观察到。我们列出了可以发现这种激发的某些高对称力量的磁性空间组。
Time reversal ($T$) and space inversion are symmetries of our universe in the low-energy limit. Fundamental theorems relate their corresponding quantum numbers to the spin for elementary particles: $\hat{T}^2=(\hat{P}\hat{T})^2=-1$ for half-odd-integer spins and $\hat{T}^2=(\hat{P}\hat{T})^2=+1$ for integer spins. Here we show that for elementary excitations in magnetic materials, this "locking" between quantum numbers is lifted: $\hat{T}^2$ and $(\hat{P}\hat{T})^2$ take all four combinations of $+1$ and $-1$ regardless of the value of the spin, where $T$ now represents the composite symmetry of time reversal and lattice translation. Unlocked quantum numbers lead to new forms of minimal coupling between these excitations and external fields, enabling novel physical phenomena such as the "cross-Lamor precession", indirectly observable in a proposed light-absorption experiment. We list the magnetic space groups with certain high-symmetry momenta where such excitations may be found.
