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Z Wasilewski

Publications and source records attributed to Z Wasilewski.

14 recordsLinked to original sources
PubMed2004

Excitonic energy shell structure of self-assembled InGaAs/GaAs quantum dots.

Performing optical spectroscopy of highly homogeneous quantum dot arrays in ultrahigh magnetic fields, an unprecedently well resolved Fock-Darwin spectrum is observed. The existence of up to four degenerate electronic shells is demonstrated where the magnetic field lifts the initial degeneracies, which reappear when levels with different angular momenta come into resonance. The resulting level shifting and crossing pattern also show evidence of many-body effects such as the mixing of configurations and exciton condensation at the resonances.

Journal Article↗
PubMed2003

Exciton dephasing in quantum dot molecules.

We have measured the exciton dephasing time in InAs/GaAs quantum dot molecules having different interdot barrier thicknesses in the temperature range from 5 to 60 K, using a highly sensitive four-wave mixing heterodyne technique. At 5 K dephasing times of several hundred picoseconds are found. Moreover, a systematic dependence of the dephasing dynamics on the barrier thickness is observed. These results show how the quantum-mechanical coupling of the electronic wave functions in the molecules affects both the exciton radiative lifetime and the exciton-acoustic phonon interaction.

Journal Article↗
PubMed2003

Fine structure of excitons in InAs/GaAs coupled auantum dots: a sensitive test of electronic coupling.

Exciton fine structure in InAs/GaAs coupled quantum dots has been studied by photoluminescence spectroscopy in magnetic fields up to 8 T. Pronounced anticrossings and mixings of optically bright and dark states as functions of magnetic field are seen. A theoretical treatment of the mixing of the excitonic states has been developed, and it traces observed features to structural asymmetries. These results provide direct evidence for coherent coupling of excitons in quantum dot molecules.

Journal Article↗
PubMed1997

[Results of surgical treatment for Dupuytren contracture].

Early and late results of surgical treatment for Dupuytren contracture within 53 hands in 47 patients aged 19-72 (mean 58) are presented. Early results depended on magnitude of deformity and late ones (3-7 years after surgery) depended on recurrence of the contracture. In patients who had rheumatoid arthritis or the results were slightly worse; pathological changes within the hand were to blame and not the recurrence of contracture itself. No difference in histopathology of this condition was observed between rheumatoid arthritis-group- and ankylosing spondylitis patients.

Adult↗
PubMed1990

[Surgical treatment of metacarpo-phalangeal joints in patients with rheumatoid arthritis].

The results of surgical treatment of 195 metacarpo-phalangeal joints in 132 rheumatoid patients were evaluated. The indications for each of three operative methods were presented with clinical assessment and Larsen, Dahle, Eek scale of radiological changes taken into consideration. The results of 137 synovectomies, 32 joint replacements and 24 arthroplasties in 88% were rated as good and fair. The advantages of early synovectomy as well as joint replacement in advanced arthritis were underlined.

Adult↗