The Origin of Quantum Noise

David I. Hoult, Naomi S. Ginsberg

Jian Leng, Fan Yang, Xiang‐Bin Wang

We present theoretical and experimental studies on efficient quantum search with noise. We propose a noise-tolerant method that significantly reduces the running time and exponentially improves the error threshold with number of qubits for Grover's search. Experiments are implemented on different quantum computing setups, with all results clearly confirming the advantage of our noise-tolerant method to the original Grover's search. In one setup, our method produces quantum advantages while the original Grover's search does not. In another setup with smaller noise, our method produces a larger quantum advantage than the original Grover's search does.

W. H. Louisell

Charles M. Bowden, John C. Englund

Keith R. Fratus, Kirsten Bark, Nicolas Vogt +4 more

We consider the extent to which a Trotterized time evolution implemented on a quantum computer is altered by the presence of decoherence. Given a specific set of assumptions regarding the manner in which noise processes acting on such a device can be modeled at the circuit level, we show how the effects of noise can be reinterpreted as a shift to the dynamics of the original system being simulated. In particular, we find that this shift can be described through the use of static Lindblad noise terms, which act in addition to the original unitary dynamics. The form of these noise terms depends not only on the underlying noise processes occurring on the device, but also on the original unitary dynamics, as well as the manner in which these dynamics are simulated on the device, i.e., the choice of quantum algorithm. We call this effectively simulated open quantum system the noisy algorithm model. Our results are confirmed through numerical analysis.

Supriyo Dutta, Subhashish Banerjee, Monika Rani

Abstract In this work, we analyze a number of noisy quantum channels on a family of qudit states. The channels studied are the dit-flip noise, phase flip noise, dit-phase flip noise, depolarizing noise, non-Markovian Amplitude Damping Channel (ADC), dephasing noise, and depolarization noise. To gauge the effect of noise, the fidelity between the original and the final states is studied. The change of coherence under the action of noisy channels is also studied, both analytically and numerically. Our approach is advantageous as it has an explicit relation to the original approach to the multi-qubit hypergraph states.