Quantum spectroscopy with Schrödinger-cat states

M. Kira, S. W. Koch, R. P. Smith, A. E. Hunter, S. T. Cundiff

Research output: Contribution to journalArticlepeer-review

77 Scopus citations


Laser-spectroscopic techniques that exploit light-matter entanglement promise access to many-body configurations. Their practical implementation, however, is hindered by the large number of coupled states involved. Here, we introduce a scheme to deal with this complexity by combining quantitative experiments with theoretical analysis. We analyse the absorption properties of semiconductor quantum wells and present a converging cluster-expansion transformation that robustly projects a large set of quantitative classical measurements onto the true quantum responses. Classical and quantum sources are shown to yield significantly different results; Schrödinger-cat states can enhance the signal by an order of magnitude. Moreover, squeezing of the source can help to individually control and characterize excitons, biexcitons and electron-hole complexes.

Original languageEnglish (US)
Pages (from-to)799-804
Number of pages6
JournalNature Physics
Issue number10
StatePublished - Oct 2011

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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