Ideal Negative Measurements in Quantum Walks Disprove Theories Based on Classical Trajectories
We report on a stringent test of the nonclassicality of the motion of a massive quantum particle, which propagates on a discrete lattice. Measuring temporal correlations of the position of single atoms performing a quantum walk, we observe a 6σ violation of the Leggett-Garg inequality. Our results r...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2015-01-01
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| Series: | Physical Review X |
| Online Access: | http://doi.org/10.1103/PhysRevX.5.011003 |
| _version_ | 1818893763309731840 |
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| author | Carsten Robens Wolfgang Alt Dieter Meschede Clive Emary Andrea Alberti |
| author_facet | Carsten Robens Wolfgang Alt Dieter Meschede Clive Emary Andrea Alberti |
| author_sort | Carsten Robens |
| collection | DOAJ |
| description | We report on a stringent test of the nonclassicality of the motion of a massive quantum particle, which propagates on a discrete lattice. Measuring temporal correlations of the position of single atoms performing a quantum walk, we observe a 6σ violation of the Leggett-Garg inequality. Our results rigorously excludes (i.e., falsifies) any explanation of quantum transport based on classical, well-defined trajectories. We use so-called ideal negative measurements—an essential requisite for any genuine Leggett-Garg test—to acquire information about the atom’s position, yet avoiding any direct interaction with it. The interaction-free measurement is based on a novel atom transport system, which allows us to directly probe the absence rather than the presence of atoms at a chosen lattice site. Beyond the fundamental aspect of this test, we demonstrate the application of the Leggett-Garg correlation function as a witness of quantum superposition. Here, we employ the witness to discriminate different types of walks spanning from merely classical to wholly quantum dynamics. |
| first_indexed | 2024-12-19T18:17:46Z |
| format | Article |
| id | doaj.art-a1d36a1c93c04cb9ba8bb5469bb83ae1 |
| institution | Directory Open Access Journal |
| issn | 2160-3308 |
| language | English |
| last_indexed | 2024-12-19T18:17:46Z |
| publishDate | 2015-01-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review X |
| spelling | doaj.art-a1d36a1c93c04cb9ba8bb5469bb83ae12022-12-21T20:11:04ZengAmerican Physical SocietyPhysical Review X2160-33082015-01-015101100310.1103/PhysRevX.5.011003Ideal Negative Measurements in Quantum Walks Disprove Theories Based on Classical TrajectoriesCarsten RobensWolfgang AltDieter MeschedeClive EmaryAndrea AlbertiWe report on a stringent test of the nonclassicality of the motion of a massive quantum particle, which propagates on a discrete lattice. Measuring temporal correlations of the position of single atoms performing a quantum walk, we observe a 6σ violation of the Leggett-Garg inequality. Our results rigorously excludes (i.e., falsifies) any explanation of quantum transport based on classical, well-defined trajectories. We use so-called ideal negative measurements—an essential requisite for any genuine Leggett-Garg test—to acquire information about the atom’s position, yet avoiding any direct interaction with it. The interaction-free measurement is based on a novel atom transport system, which allows us to directly probe the absence rather than the presence of atoms at a chosen lattice site. Beyond the fundamental aspect of this test, we demonstrate the application of the Leggett-Garg correlation function as a witness of quantum superposition. Here, we employ the witness to discriminate different types of walks spanning from merely classical to wholly quantum dynamics.http://doi.org/10.1103/PhysRevX.5.011003 |
| spellingShingle | Carsten Robens Wolfgang Alt Dieter Meschede Clive Emary Andrea Alberti Ideal Negative Measurements in Quantum Walks Disprove Theories Based on Classical Trajectories Physical Review X |
| title | Ideal Negative Measurements in Quantum Walks Disprove Theories Based on Classical Trajectories |
| title_full | Ideal Negative Measurements in Quantum Walks Disprove Theories Based on Classical Trajectories |
| title_fullStr | Ideal Negative Measurements in Quantum Walks Disprove Theories Based on Classical Trajectories |
| title_full_unstemmed | Ideal Negative Measurements in Quantum Walks Disprove Theories Based on Classical Trajectories |
| title_short | Ideal Negative Measurements in Quantum Walks Disprove Theories Based on Classical Trajectories |
| title_sort | ideal negative measurements in quantum walks disprove theories based on classical trajectories |
| url | http://doi.org/10.1103/PhysRevX.5.011003 |
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