Compact fermion to qubit mappings

Jul 8, 2021
12 pages
Published in:
  • Phys.Rev.B 104 (2021) 3, 035118
  • Published: Jul 8, 2021

Citations per year

20202021202220232024051015202530
Abstract: (APS)
Mappings between fermions and qubits are valuable constructions in physics. To date only a handful exist. In addition to revealing dualities between fermionic and spin systems, such mappings are indispensable in any quantum simulation of fermionic physics on quantum computers. The number of qubits required per fermionic mode, and the locality of mapped fermionic operators strongly impact the cost of such simulations. We present a fermion to qubit mapping that outperforms all previous local mappings in both the qubit to mode ratio and the locality of mapped operators. In addition to these practically useful features, the mapping bears an elegant relationship to the toric code, which we discuss. Finally, we consider the error mitigating properties of the mapping---which encodes fermionic states into the code space of a stabilizer code. Although there is an implicit tradeoff between low weight representations of local fermionic operators, and high distance code spaces, we argue that fermionic encodings with low-weight representations of local fermionic operators can still exhibit error mitigating properties which can serve a similar role to that played by high code distances. In particular, when undetectable errors correspond to ``natural'' fermionic noise. We illustrate this point explicitly both for this encoding and the Verstraete-Cirac encoding.
  • Quantum Information, Science & Technology
  • Condensed Matter, Materials & Applied Physics
  • Fermions
  • Quantum simulation
  • Hubbard model
  • Quantum chemistry methods
  • fermion: local
  • chemistry: quantum
  • qubit
  • quantum simulation