Physics Dept Seminar

 

October 14, Monday

 

Materials with Broken Mirror Symmetries

 

Prof. Junjie Yang

Dept of Physics, NJIT

(Materials Physics, Host: Tyson)

 

Time: 11:45 am - 12:45 pm with 11:30 am teatime

Room: ECE 202

 

Material properties are governed by fundamental symmetries, such as space inversion, mirror reflection, and time-reversal symmetries. New material functionalities can only emerge when these symmetries are broken. For example, breaking space inversion symmetry can induce ferroelectricity, while breaking time-reversal symmetry can result in ferromagnetism. Both ferroelectric and ferromagnetic materials have played crucial roles in modern technologies and industries. Materials with broken mirror reflection symmetries are relatively less studied, although a broad family of such materials exists. Breaking mirror symmetry can give rise to various exotic phenomena, especially when materials are subjected to external electric or magnetic fields or interact with spin ordering. These phenomena include electric field-induced chirality, non-reciprocal spin waves, and magnetic order-induced ferro-rotational order. In this talk, we will discuss emergent material functionalities in several typical materials with broken mirror symmetries, such as RbFe(SO₄)₂, Ni₃TeO₆, and M₁/₃TaS₂.