A magnon is a quasiparticle, a collective excitation of the spin structure of an electron in a crystal lattice. In the equivalent wave picture of quantum mechanics, a magnon can be viewed as a quantized spin wave. Magnons carry a fixed amount of energy and lattice momentum, and are spin-1, indicating they obey boson behavior.
A magnon is a quasiparticle, a collective excitation of the spin structure of an electron in a crystal lattice. In the equivalent wave picture of quantum mechanics, a magnon can be viewed as a quantized spin wave. Magnons carry a fixed amount of energy and lattice momentum, and are spin-1, indicating they obey boson behavior.
== History == Felix Bloch introduced the concept of a magnon in 1930 to explain the reduction of the spontaneous magnetization in a ferromagnet. At absolute zero temperature (0 K), a Heisenberg ferromagnet reaches the state of lowest energy (so-called ground state), in which all of the atomic spins (and hence magnetic moments) point in the same direction. As the temperature increases, more and more spins deviate randomly from the alignment, increasing the internal energy and reducing the net magnetization. Viewing the perfectly magnetized state at zero temperature as the vacuum state of the ferromagnet, shows the low-temperature state with a few misaligned spins as a gas of quasiparticles, in this case magnons. Each magnon reduces the total spin along the direction of magnetization by one unit of \hbar (the reduced Planck constant) and the magnetization by \gamma\hbar, where \gamma is the gyromagnetic ratio. This leads to Bloch's law for the temperature dependence of spontaneous magnetization: M(T) = M_0 \left[1 - \left(\frac{T}{T_\text{c}}\right)^{3/2}\right] where T_\text{c} is the (material dependent) critical temperature, and M_0 is the magnitude of the spontaneous magnetization.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).