Fiber bundle codes: breaking the n1/2 polylog(n) barrier for Quantum LDPC codes

We present a quantum LDPC code family that has distance Ω(N 3/5 / polylog(N )) and Θ(N 3/5 ) logical qubits, where N is the code length. This is the first quantum LDPC code construction which achieves distance greater than N 1/2 polylog(N ). The construction is based on generalizing the homological product of codes to a fiber bundle. * Station Q. and Microsoft Quantum. † Station Q. and Microsoft Quantum.