Quantum driving of a two level system: quantum speed limit and superadiabatic protocols - an experimental investigation
| Autor: | E. Arimondo, Riccardo Mannella, Nicola Malossi, Oliver Morsch, Mark G. Bason, Matthieu Viteau, Donatella Ciampini |
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| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Physics
History Quantum limit Quantum capacity transitionless protocols Adiabatic quantum computation Computer Science Applications Education Classical mechanics Quantum state Quantum process Quantum system Quantum algorithm Statistical physics Amplitude damping channel Quantum speed limit Quantum speed limit adiabaticity transitionless protocols adiabaticity |
| Zdroj: | 6th International Workshop on Decoherence, Information, Complexity and Entropy (DICE), pp. 012062–012062, Castiglioncello, ITALY, SEP 17-21, 2012 info:cnr-pdr/source/autori:Malossi, N.; Bason, M. G.; Viteau, M.; Arimondo, E.; Ciampini, D.; Mannella, R.; Morsch, O./congresso_nome:6th International Workshop on Decoherence, Information, Complexity and Entropy (DICE)/congresso_luogo:Castiglioncello, ITALY/congresso_data:SEP 17-21, 2012/anno:2013/pagina_da:012062/pagina_a:012062/intervallo_pagine:012062–012062 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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