Figure 1

(a) The experimental setup (see also Ref. [6]) is mounted on a rotational table inside of a Helmholtz coil system and a mu-metal shielding. The orientation of the setup concerning the created magnetic field is adjusted by a cable pull. (b) The vapor cell used for our experimental investigations features two circularly shaped active volumes and a rectangular reservoir. (c) The schematic drawing of the setup viewed from the side for rotating angles of \(\alpha = 0\) includes the optics for generating two circularly polarized laser beams. The axis of rotation is parallel to the y-axis. The pump (PL) and heat laser (HL) are colored in red and blue, respectively. The whole optical setup can be rotated inside the magnetic field \(\vec{B}_{0}\) that is fixed along the z-axis