Quantum driving of a two level system: quantum speed limit and superadiabatic protocols – an experimental investigation

A fundamental requirement in quantum information processing and in many other areas of science is the capability of precisely controlling a quantum system by preparing a quantum state with the highest fidelity and/or in the fastest possible way. Here we present an experimental investigation of a two...

Full description

Saved in:
Bibliographic Details
Published in:Journal of physics. Conference series 2013-01, Vol.442 (1), p.12062-9
Main Authors: Malossi, N, Bason, M G, Viteau, M, Arimondo, E, Ciampini, D, Mannella, R, Morsch, O
Format: Article
Language:English
Subjects:
Accuracy
Adiabatic flow
Bose-Einstein condensates
Control systems
Data processing
Optical lattices
Optimization
Parameters
Physics
Quantum mechanics
Quantum phenomena
Quantum theory
Speed limits
Time dependence
Transformations
Unity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A fundamental requirement in quantum information processing and in many other areas of science is the capability of precisely controlling a quantum system by preparing a quantum state with the highest fidelity and/or in the fastest possible way. Here we present an experimental investigation of a two level system, characterized by a time-dependent Landau-Zener Hamiltonian, aiming to test general and optimal high-fidelity control protocols. The experiment is based on a Bose-Einstein condensate (BEC) loaded into an optical lattice, then accelerated, which provides a high degree of control over the experimental parameters. We implement generalized Landau-Zener sweeps, comparing them with the well-known linear Landau-Zener sweep. We drive the system from an initial state to a final state with fidelity close to unity in the shortest possible time (quantum brachistochrone), thus reaching the ultimate speed limit imposed by quantum mechanics. On the opposite extreme of the quantum control spectrum, the aim is not to minimize the total transition time but to maximize the adiabaticity during the time-evolution, the system being constrained to the adiabatic ground state at any time. We implement such transitionless superadiabatic protocols by an appropriate transformation of the Hamiltonian parameters. This transformation is general and independent of the physical system.
ISSN:1742-6596
1742-6588
1742-6596
DOI:10.1088/1742-6596/442/1/012062