  Weyl semimetals are phases of matter with gapless electronic excitations that
are protected by topology and symmetry. Their properties depend on the
dimensions of the systems. It has been theoretically demonstrated that
five-dimensional (5D) Weyl semimetals emerge as novel phases during the
topological phase transition in analogy to the three-dimensional case. However,
experimental observation of such a phenomenon remains a great challenge because
the tunable 5D system is extremely hard to construct in real space. Here, we
construct 5D electric circuit platforms in fully real space and experimentally
observe topological phase transitions in five dimensions. Not only are Yang
monopoles and linked Weyl surfaces observed experimentally, but various phase
transitions in five dimensions are also proved, such as the phase transitions
from a normal insulator to a Hopf link of twoWeyl surfaces and then to a 5D
topological insulator. The demonstrated topological phase transitions in five
dimensions leverage the concept of higher-dimensional Weyl physics to control
electrical signals in the engineered circuits.
