Quantum Coherence of Strongly Correlated Defects in Spin Chains

Sylvain Bertaina (1) , Charles-Emmanuel Dutoit (1) , Johan van Tol (2) , Martin Dressel (3) , Bernard Barbara (4) , Anatoli Stepanov (1)

1 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
2 NHMFL - National High Magnetic Field Laboratory
3 Pfaffenwaldring 57, D–70550 Stuttgart, Germany - Physikalisches Institut [Stuttgart]
4 NEEL - QuantECA - Circuits électroniques quantiques Alpes

Most of qubit systems known to date are isolated paramagnetic centres in magnetically diluted samples since their dilution allows to considerably weaken the dipole-dipole inter-qubit interaction and thus to prevent the decoherence. Here we suggest an alternative approach for spin qubits which are built on spin S = 1/2 defects in magnetically concentrated strongly correlated systems-spin chains. The corresponding qubits are made of spin solitons resulting from local breaking of transitional symmetry associated with point-defects. We provide the first evidence for coherence and Rabi oscillations of spin solitons in isotropic Heisenberg chains, simple antiferromagnetic-Néel or spin-Peierls, proving that they can be manipulated as single spin S = 1/2. The entanglement of these many-body soliton states over macroscopic distances along chains gives rise to networks of coupled qubits which could easily be decoupled at will in extensions of this work.

Mots clés: EPR; Quantum coherence; strongly correlated magnet

Domaines: Matière Condensée [cond-mat]; Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Sylvain Bertaina, Charles-Emmanuel Dutoit, Johan van Tol, Martin Dressel, Bernard Barbara, et al.. Quantum Coherence of Strongly Correlated Defects in Spin Chains. Physics Procedia, 2015, 75 (18), pp.23 - 28. ⟨10.1016/j.phpro.2015.12.004⟩. ⟨hal-01659940⟩