  Chirality-induced spin selectivity (CISS) has been extensively studied over
the past two decades. While current-induced spin polarization in chiral
molecules is widely recognized as the fundamental principle of the CISS, only a
few studies have been reported on bias-current-free CISS, where there is no
bias electric current in chiral molecules. Recent studies on the
chirality-induced exchange bias and current-in-plane magnetoresistance (CIP-MR)
effects using chiral molecule/ferromagnet bilayer systems indicate that chiral
molecules at the interface possess thermally driven broken-time-reversal
symmetry, which induces bias-current-free CISS, i.e. a spontaneous effective
magnetic field in the system. In this paper, we briefly review CISS-related
phenomena in terms of the symmetry and discuss the mechanism of
bias-current-free CISS. We also discuss the possibility of the linear
magnetoelectric effect of chiral molecules, which arises from the spin
polarization at the edges of molecules with metallic contacts, and its
potential impact on the observed CISS phenomena.
