Chien-An Wang

Simulations using engineered and highly tunable quantum systems may enable investigations of
condensed matter systems beyond the capabilities of classical computers. This includes the study of
highly-correlated electronic phases that are predicted to have exotic properties, such as resonating
valence bond states. Here, we introduce hole spin quantum dots defined in planar germanium
quantum wells as a promising platform for quantum simulation. We demonstrate extensive and
coherent control over the exchange coupling, which enables the tuning of multi-spin states in isolated,
paired, and fully coupled quantum dots. We probe characteristics of valence bond resonances and
measure the coherent evolution between singlet product states. Furthermore, we demonstrate the
formation of both the s-wave and d-wave eigenstates of the system. These results provide means
for the construction of decoherence-free subspaces for quantum computation, as well as to perform
non-trivial simulations of correlated electron systems.