Abstract

This review surveys high-order Van Hove singularities (HOVHS) in electronic band structures, emphasizing their relation to nearly flat bands. It discusses how tuning by strain, pressure, twisting angle, magnetic field, gate and bias voltage can drive ordinary critical points into higher-order ones, the resulting power-law singular density of states, classification schemes, interaction effects, and experimental evidence in materials such as strontium ruthenates, kagome metals, graphene systems, and moiré materials.

Abstract

This review surveys high-order Van Hove singularities (HOVHS) in electronic band structures, emphasizing their relation to nearly flat bands. It discusses how tuning by strain, pressure, twisting angle, magnetic field, gate and bias voltage can drive ordinary critical points into higher-order ones, the resulting power-law singular density of states, classification schemes, interaction effects, and experimental evidence in materials such as strontium ruthenates, kagome metals, graphene systems, and moiré materials.

Abstract

This review surveys high-order Van Hove singularities (HOVHS) in electronic band structures, emphasizing their relation to nearly flat bands. It discusses how tuning by strain, pressure, twisting angle, magnetic field, gate and bias voltage can drive ordinary critical points into higher-order ones, the resulting power-law singular density of states, classification schemes, interaction effects, and experimental evidence in materials such as strontium ruthenates, kagome metals, graphene systems, and moiré materials.

Abstract

This review surveys high-order Van Hove singularities (HOVHS) in electronic band structures, emphasizing their relation to nearly flat bands. It discusses how tuning by strain, pressure, twisting angle, magnetic field, gate and bias voltage can drive ordinary critical points into higher-order ones, the resulting power-law singular density of states, classification schemes, interaction effects, and experimental evidence in materials such as strontium ruthenates, kagome metals, graphene systems, and moiré materials.