  An atomic magnetometer operated with elliptically polarized light is
investigated theoretically and experimentally. To explore the potential of this
magnetometric configuration, the analytical form of the outgoing signal is
derived. Parameters that significantly influence the performance are optimized,
which lead to a sensitivity of 300 $\rm fT/\sqrt{Hz}$ at 45 $^{\circ}$C with a
2$\times$2$\times2$ cm uncoated Rb vapor cell. It is remarkable that a
sensitivity of 690 $\rm fT/\sqrt{Hz}$ is achieved at room temperature of 24
$^{\circ}$C, which is improved by an order of magnitude compared with the
conventional $M_x$ magnetometer under its own optimized condition. The
elliptically polarized approach offers attractive features for developing
compact, low-power magnetometers, which are available without heating the
uncoated vapor cell.
