Quantum Zeno effect in correlated qubits

TL;DR

This paper investigates how the quantum Zeno effect influences the speed of quantum information processing in correlated qubits, revealing that interactions can induce or prevent the effect based on system design.

Contribution

It demonstrates the impact of quantum Fisher information on processing speed and shows how correlations can be engineered to control the quantum Zeno effect in quantum computers.

Findings

Frequent interactions induce the quantum Zeno effect.

Correlations can prevent the Zeno effect.

Implications for designing faster quantum information processing.

Abstract

Near term quantum hardware promises to achieve quantum supremacy. From a quantum dynamical point of view, however, it is not unambiguously clear whether fundamental peculiarities of quantum physics permit any arbitrary speed-ups in real time. We show that an only recently unveiled property of the quantum Fisher information has profound implications for the rate of possible quantum information processing. To this end, we analyze an exemplary and pedagogical example for a quantum computer consisting of a computational qubit and a quantum memory. We find that frequent interaction between memory and device exhibit the quantum Zeno effect. In a second part, we show that the Zeno effect can be prevented by carefully designing the correlations and interaction between single elements of the quantum memory.