Fermion-to-Fermion Low-Density Parity-Check Codes

Abstract: Simulating fermionic systems on qubit-based quantum computers often demands significant computational resources due to the requirement to map fermions to qubits. Thus, designing a fault-tolerant quantum computer that operates directly with fermions offers an effective solution to this challenge. Here, we introduce a protocol for fault-tolerant fermionic quantum computation utilizing fermion-to-fermion low-density parity-check codes. Our method employs a fermionic low-density parity-check code memory, which transfers its state to fermionic color code processors assisted by lattice surgery, where logical operations are subsequently performed. To construct the fermionic low-density parity-check memory, we develop a systematic approach for creating fermionic stabilizer codes based on self-dual Calderbank-Shor-Steane codes. We present examples demonstrating these codes' significantly improved coding rate compared to the fermionic color code. Finally, we simulate the dynamics of a fermionic system using our protocol, illustrating effective error suppression.