Zeeman-type energy level splittings controlled by an electric field

Two-level systems are at the heart of quantum information and quantum computation based on qubits. The manipulation of Zeeman-type energy-level splittings is crucial for utilizing two-level systems hosted by electronic spin or pseudospin in crystalline materials. Of particular interest are Zeeman-type energy level splittings controlled by the electric field, most of which were realized in materials involving both spin and nonspin degrees of freedom that are entangled strongly via spin-orbital interaction. Here, we provide a strategy enabling the electric-field control of Zeeman-type energy-level splitting rooted in the nonspin degree of freedom of electrons???essentially from sublattice/atomic orbitals???in materials containing nonsymmorphic symmetry elements (e.g., glide plane or screw axis). The physical origin of such a Zeeman-type splitting is revealed as the breakdown of the specific nonsymmorphic symmetry elements by electric field. We further propose, via first-principles simulations, a platform system of CaTiO3 under tensile strain (ferroelectric compound) that accommodates a large Zeeman-type energy-level splitting of -124 meV, controllable by the electric field.

Automated summary

This study explores how to control the Zeeman-type energy-level splitting of a two-level system in a material like calcium titanate (CaTiO3) using an electric field, aiming to achieve quantum information and quantum computation. The strategy for achieving this control is based on understanding the breakdown of specific nonsymmorphic symmetry elements by the electric field, affecting the nonspin degree of freedom of electrons in the material. Through first-principles simulations, a platform system of CaTiO3 under tensile strain is proposed as a candidate for achieving a large Zeeman-type energy-level splitting controllable by the electric field.