Partitioning dysprosium's electronic spin to reveal entanglement in nonclassical states
Quantum spins of mesoscopic size are a well-studied playground for engineering nonclassical states. If the spin represents the collective state of an ensemble of qubits, its nonclassical behavior is linked to entanglement between the qubits. In this paper, we report on an experimental study of entan...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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American Physical Society
2021-10-01
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| Series: | Physical Review Research |
| Online Access: | http://doi.org/10.1103/PhysRevResearch.3.043001 |
| _version_ | 1797210933845557248 |
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| author | Tanish Satoor Aurélien Fabre Jean-Baptiste Bouhiron Alexandre Evrard Raphael Lopes Sylvain Nascimbene |
| author_facet | Tanish Satoor Aurélien Fabre Jean-Baptiste Bouhiron Alexandre Evrard Raphael Lopes Sylvain Nascimbene |
| author_sort | Tanish Satoor |
| collection | DOAJ |
| description | Quantum spins of mesoscopic size are a well-studied playground for engineering nonclassical states. If the spin represents the collective state of an ensemble of qubits, its nonclassical behavior is linked to entanglement between the qubits. In this paper, we report on an experimental study of entanglement between two subsystems of dysprosium's electronic spin. Its ground state, of angular momentum J=8, can formally be viewed as a set of 2J qubits symmetric upon exchange. To access entanglement properties, we partition the spin by optically coupling it to an excited state J^{′}=J−1, which removes a pair of qubits in a state defined by the light polarization. Starting with the well-known W and squeezed states, we extract the concurrence of qubit pairs, which quantifies their nonclassical character. We also directly demonstrate entanglement between the 14- and 2-qubit subsystems via an increase in entropy upon partition. In a complementary set of experiments, we probe decoherence of a state prepared in the excited level J^{′}=J+1 and interpret spontaneous emission as a loss of a qubit pair in a random state. This allows us to contrast the robustness of nonclassical pairwise correlations of the W state with the fragility of the coherence involved in a Schrödinger cat state. Our findings open up the possibility to engineer novel types of entangled atomic ensembles, in which entanglement occurs within each atom's electronic spin as well as between different atoms. Qubit ensembles with large entanglement depth could then be realized with a few atoms only, facilitating the scaling up of quantum-enhanced sensors. |
| first_indexed | 2024-04-24T10:18:28Z |
| format | Article |
| id | doaj.art-767327861330432593a1c768e2ed8be2 |
| institution | Directory Open Access Journal |
| issn | 2643-1564 |
| language | English |
| last_indexed | 2024-04-24T10:18:28Z |
| publishDate | 2021-10-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review Research |
| spelling | doaj.art-767327861330432593a1c768e2ed8be22024-04-12T17:14:30ZengAmerican Physical SocietyPhysical Review Research2643-15642021-10-013404300110.1103/PhysRevResearch.3.043001Partitioning dysprosium's electronic spin to reveal entanglement in nonclassical statesTanish SatoorAurélien FabreJean-Baptiste BouhironAlexandre EvrardRaphael LopesSylvain NascimbeneQuantum spins of mesoscopic size are a well-studied playground for engineering nonclassical states. If the spin represents the collective state of an ensemble of qubits, its nonclassical behavior is linked to entanglement between the qubits. In this paper, we report on an experimental study of entanglement between two subsystems of dysprosium's electronic spin. Its ground state, of angular momentum J=8, can formally be viewed as a set of 2J qubits symmetric upon exchange. To access entanglement properties, we partition the spin by optically coupling it to an excited state J^{′}=J−1, which removes a pair of qubits in a state defined by the light polarization. Starting with the well-known W and squeezed states, we extract the concurrence of qubit pairs, which quantifies their nonclassical character. We also directly demonstrate entanglement between the 14- and 2-qubit subsystems via an increase in entropy upon partition. In a complementary set of experiments, we probe decoherence of a state prepared in the excited level J^{′}=J+1 and interpret spontaneous emission as a loss of a qubit pair in a random state. This allows us to contrast the robustness of nonclassical pairwise correlations of the W state with the fragility of the coherence involved in a Schrödinger cat state. Our findings open up the possibility to engineer novel types of entangled atomic ensembles, in which entanglement occurs within each atom's electronic spin as well as between different atoms. Qubit ensembles with large entanglement depth could then be realized with a few atoms only, facilitating the scaling up of quantum-enhanced sensors.http://doi.org/10.1103/PhysRevResearch.3.043001 |
| spellingShingle | Tanish Satoor Aurélien Fabre Jean-Baptiste Bouhiron Alexandre Evrard Raphael Lopes Sylvain Nascimbene Partitioning dysprosium's electronic spin to reveal entanglement in nonclassical states Physical Review Research |
| title | Partitioning dysprosium's electronic spin to reveal entanglement in nonclassical states |
| title_full | Partitioning dysprosium's electronic spin to reveal entanglement in nonclassical states |
| title_fullStr | Partitioning dysprosium's electronic spin to reveal entanglement in nonclassical states |
| title_full_unstemmed | Partitioning dysprosium's electronic spin to reveal entanglement in nonclassical states |
| title_short | Partitioning dysprosium's electronic spin to reveal entanglement in nonclassical states |
| title_sort | partitioning dysprosium s electronic spin to reveal entanglement in nonclassical states |
| url | http://doi.org/10.1103/PhysRevResearch.3.043001 |
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