Quantum measurement and thermally assisted proton tunnelling

Abstract

Despite compelling evidence to the contrary in recent years, the view still persists that quantum effects cannot survive very long within a warm, noisy and complex environment that washes out quantum effects at timescales far too short for any chemically or biochemically interesting processes. It is also assumed that as the temperature of the surrounding environment increases, so the efficiency of processes such as quantum tunnelling drops. One way of viewing this has been to invoke the quantum Zeno effect: that the watched pot never boils. In this work we show that the opposite is true. For a quite general open quantum system, a proton in an asymmetric double-well potential, the action of the environment is to enhance the tunnelling rate (an anti-Zeno effect). We compare two simple mathematical models to show that, over a specific temperature range, thermally enhanced quantum tunnelling is equivalent to increasing the frequency of a von Neumann-type measurement by the environment on the system.