Quantum 9, 1730 (2025). https://doi.org/10.22331/q-2025-05-05-1730 For random quantum circuits on $n$ qubits of depth $Theta(log n)$ with depolarizing noise, the task of sampling from the output state can be efficiently performed classically using a Pauli […]
Quantum 9, 1729 (2025). https://doi.org/10.22331/q-2025-05-05-1729 Non-Hermitian dynamics in quantum systems preserves the rank of the state density operator. Using this insight, we develop a geometric framework to describe its time evolution. In particular, we identify […]
Quantum 9, 1728 (2025). https://doi.org/10.22331/q-2025-05-05-1728 Constant-rate low-density parity-check (LDPC) codes are promising candidates for constructing efficient fault-tolerant quantum memories. However, if physical gates are subject to geometric-locality constraints, it becomes challenging to realize these codes. […]
Quantum 9, 1727 (2025). https://doi.org/10.22331/q-2025-05-05-1727 Error mitigation will play an important role in practical applications of near-term noisy quantum computers. Current error mitigation methods typically concentrate on correction quality at the expense of frugality (as […]
Quantum 9, 1726 (2025). https://doi.org/10.22331/q-2025-05-05-1726 We present an iterative generalisation of the quantum subspace expansion algorithm used with a Krylov basis. The iterative construction connects a sequence of subspaces via their lowest energy states. Diagonalising […]
Quantum 9, 1725 (2025). https://doi.org/10.22331/q-2025-05-05-1725 We study the estimation of relative entropy $D(rho|sigma)$ when $sigma$ is known. We show that the Cramér-Rao type bound equals the relative varentropy. Our estimator attains the Cramér-Rao type bound […]
Quantum 9, 1724 (2025). https://doi.org/10.22331/q-2025-05-05-1724 Current noisy quantum computers have multiple types of errors, which can occur in the state preparation, measurement/readout, and gate operation, as well as intrinsic decoherence and relaxation. Partly motivated by […]
Quantum 9, 1723 (2025). https://doi.org/10.22331/q-2025-05-05-1723 In this work, we introduce a method to construct fault-tolerant $textit{measurement-based quantum computation}$ (MBQC) architectures and numerically estimate their performance over various types of networks. A possible application of such […]
Quantum 9, 1722 (2025). https://doi.org/10.22331/q-2025-04-24-1722 One significant advantage of superconducting processors is their extensive design flexibility, which encompasses various types of qubits and interactions. Given the large number of tunable parameters of a processor, the […]
Quantum 9, 1721 (2025). https://doi.org/10.22331/q-2025-04-24-1721 Motivated by the expectation that relativistic symmetries might acquire quantum features in Quantum Gravity, we take the first steps towards a theory of ”Doubly” Quantum Mechanics, a modification of Quantum […]
Recent Comments