Long-lived spin coherence of indirect excitons in GaAs coupled quantum wells Mussie Beian, Mathieu Alloing, Edmond Cambril, Carmen Gomez Carbonell, Johann Osmond, Aristide Lemaître and François Dubin EPL, 110 2 (2015) 27001 Published online: 01 May 2015 DOI: 10.1209/0295-5075/110/27001