Emre Sahin, Matthew Madgwick, et al.
QCE 2025
We present a method for encoding second-quantized fermionic systems in qubits when the number of fermions is conserved, as in the electronic structure problem. When the number F of fermions is much smaller than the number M of modes, this symmetry reduces the number of information-theoretically required qubits from Θ(M) to O(FlogM). In this limit, our encoding requires O(F2log4M) qubits, while encoded fermionic creation and annihilation operators have cost O(F2log5M) in two-qubit gates. When incorporated into randomized simulation methods, this permits simulating time evolution with only polylogarithmic explicit dependence on M. This is the first second-quantized encoding of fermions in qubits whose costs in qubits and gates are both polylogarithmic in M, which permits studying fermionic systems in the high-accuracy regime of many modes.
Emre Sahin, Matthew Madgwick, et al.
QCE 2025
Mario Motta, William Kirby, et al.
Electronic Structure
Zanhe Qi, Atsushi Matsuo, et al.
QCE 2024
Christa Zoufal, Stefan Woerner
APS March Meeting 2023