RT Journal Article T1 Phase dependence of localization in the driven two-level model A1 Creffield, Charles AB A two-level system subjected to a high-frequency driving field can exhibit an effect termed "coherent destruction of tunneling", in which the tunneling of the system is suppressed at certain values of the frequency and strength of the field. This suppression becomes less effective as the frequency of the driving field is reduced, and we show here how the detailed form of its fall-off depends on the phase of the driving, which for certain values can produce small local maxima (or revivals) in the overall decay. By considering a square-wave driving field, which has the advantage of being analytically tractable, we show how this surprising behavior can be interpreted geometrically in terms of orbits on the Bloch sphere. These results are of general applicability to more commonly used fields, such as sinusoidal driving, which display a similar phenomenology. PB European Physical Society SN 0295-5075 YR 2004 FD 2004-06 LK https://hdl.handle.net/20.500.14352/51862 UL https://hdl.handle.net/20.500.14352/51862 LA eng NO © EDP Sciences.The author gratefully acknowledges the hospitality of the University of Edinburgh, where this work was completed. DS Docta Complutense RD 9 abr 2025