New pre-print “Ground State Energy via Adiabatic Evolution and Phase Measurement for a Molecular Hamiltonian on an Ion-Trap Quantum Computer”
Ludwig Nützel, alongside Michael J. Hartmann, Henrik Dreyer, and Etienne Granet, have released a new pre-print on the arXiv, titled “Ground State Energy via Adiabatic Evolution and Phase Measurement for a Molecular Hamiltonian on an Ion-Trap Quantum Computer”.
In this work, they implement adiabatic state preparation (ASP) and a noise-resilient iterative quantum phase estimation (iQPE) protocol on a trapped-ion quantum computer to estimate the ground-state energy of the H₃⁺ molecule. It constitutes the largest experiment of its kind to date: six system qubits and one ancilla, for a total of ~1000 two-qubit gates per circuit. The authors also identify leakage as the dominant source of error – far more impactful than coherent or incoherent noise. Without leakage, simulations show they would have reached near chemical accuracy. Still, and despite the leakage, energy estimates achieved are better than classical Hartree–Fock. These findings demonstrate that suppressing leakage will be critical for future algorithms and hardware development.
Ludwig Nützel thanks Henrik Dreyer and Etienne Granet for their collaboration.