  Weyl semimetals (WSMs) are three-dimensional topological materials that
exhibit fascinating properties due to the presence of Weyl nodes in their band
structure. However, existing WSMs discovered so far often possess multiple
pairs of Weyl nodes, posing a challenge in disentangling the contributions to
transport phenomena from different energy bands. To overcome this challenge, we
have identified field-induced ferromagnetic MnBi$_{2-x}$Sb$_{x}$Te$_{4}$ as an
ideal type-II WSM with a single pair of Weyl nodes. By employing a combination
of quantum oscillations and high-field Hall measurements, we have resolved the
evolution of Fermi-surface sections as the Fermi level is tuned across the
charge neutrality point, precisely matching the band structure of an ideal
type-II WSM. Furthermore, the anomalous Hall conductivity exhibits a
heartbeat-like behavior as the Fermi level is tuned across the Weyl nodes, a
unique feature previously predicted for a type-II WSM. Our findings establish
MnBi$_{2-x}$Sb$_{x}$Te$_{4}$ as an ideal platform for further investigation
into Weyl physics.
