Probing shift-current responses in noncentrosymmetric materials using quantum algorithms

Accessing the geometric origin of shift current in noncentrosymmetric quantum materials is essential for understanding nonlinear photoresponses governed by band geometry and Berry connections. We present a quantum-algorithmic approach, implemented on a classical simulator of quantum circuits, to compute the shift current in a phase-coherent and gauge-consistent manner. By expressing the geometric ingredients of the bulk photovoltaic effect as observables accessible within a quantum-circuit framework, the method enables the evaluation of the second-order dc photocurrent without explicit gauge fixing. Using the one-dimensional Rice–Mele model as a benchmark, we obtain shift-current spectra in quantitative agreement with classical calculations and exhibiting smooth behavior across the Brillouin zone. These results position quantum algorithms as a promising framework for addressing shift-current responses and, more broadly, nonlinear optical phenomena in quantum materials.