Quark Gluon Matter in Strong Magnetic and Vortical Fields

Relativistic heavy-ion collisions generate high-temperature quark gluon plasma with extremely strong electromagnetic and fluid vortical fields. The quark gluon plasma exhibits intriguing macroscopic quantum phenomena in the presence of strong electromagnetic and vortical fields, e.g., the chiral magnetic effect, chiral vortical effects, chiral separation effect, chiral electric separation effect, and spin polarization. These phenomena provide us a unique experimental means to study the nontrivial topological sector of the quantum chromodynamics, e.g., possible parity violation of strong interaction at high temperature, and subatomic spintronics of quark gluon plasma. They are also closely related to other subfields of physics, such as particle physics, condensed matter physics, astrophysics, and cold atomic physics, and thus form a new interdisciplinary research area. The goal of the present article is to give an introduction to these phenomena and to review the current status of their experimental search in heavy-ion collisions. In particular, we find that the magnetic fields generated in heavy-ion collisions can reach 10^18\sim 10^20 G and the fluid vorticity can reach 10^22 s^–1; these are the known strongest magnetic fields and vorticity in the current universe. We quantitatively analyze the isobar collisions and find that, even if the background level is of 93%, the current isobar collisions can still test the occurrence of the chiral magnetic effect at 3\sigma significance level. We give the causal set of equations of spin hydrodynamics and give the collective modes in it; the spin hydrodynamics is useful to resolve the sign problem appearing in the comparison between theoretical calculations and experimental measurements of the spin polarization of hyperons.