Nonlinear Oscillations and Chaos in Narrow Gap              Semiconductors
{'Code': '03070003', 'Directorate': {'Abbreviation': 'MPS', 'LongName': 'Direct For Mathematical & Physical Scien'}, 'Division': {'Abbreviation': 'DMR', 'LongName': 'Division Of Materials Research'}}
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Oscillatory instabilities (but not chaos) in the electrical                     properties of semiconductors due to nonlinear effects of an                     applied electric field have been known for a long time.  The                    concept of chaos introduces a new means for analyzing and                       understanding these nonlinear semiconductor systems, and helps to               establish the physical origin of the oscillations and non-linear                behavior. A comprehensive investigation of oscillatory behavior,                bifurcation and chaos in the electrical properties of narrow gap                semiconductors (m- and p-InSb and Hg1-xCdxTe) that are controlled               by impact ionization of shallow impurities will be carried out,                 with the goal of understanding the dynamics of deterministic                    nonlinear systems of narrow gap semiconductors, especially                      chaotic ones.  Both experimental and mathematical modeling                      behavior will be investigated for period doubling tangent                       bifurcations, intermittency, quasiperiodicity, frequency locking,               strange attractors, Lyapunov exponents, chaotic states, etc.                    Effects of various parameters--sample doping, lattice                           temperature, magnetic field, sample contacts, sample                            compensation, etc. on the chaotic behavior of both n- and p- type               InSb will be studied.  Models will be developed to better                       understand semiconductor dynamics and the relationship of the                   nonlinear oscillations/chaos to the role of the impurities.  The                PI will seek to discover how the nonlinear oscillations/chaos can               be used to characterize the impurities in the samples.  The                     results should have general applicability to other semiconductors               which have similar properties.  A major emphasis will be placed                 on studies at high magnetic fields (up to 120 kG).
{'FirstName': 'Christopher', 'LastName': 'Littler', 'PI_MID_INIT': 'L', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Christopher L Littler', 'EmailAddress': 'christopher.littler@unt.edu', 'NSF_ID': '000366411', 'StartDate': '06/15/1987', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'University of North Texas', 'CityName': 'DENTON', 'ZipCode': '762051132', 'PhoneNumber': '9405653940', 'StreetAddress': '1112 DALLAS DR STE 4000', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'Texas', 'StateCode': 'TX', 'CONGRESSDISTRICT': '13', 'CONGRESS_DISTRICT_ORG': 'TX13', 'ORG_UEI_NUM': 'G47WN1XZNWX9', 'ORG_LGL_BUS_NAME': 'UNIVERSITY OF NORTH TEXAS', 'ORG_PRNT_UEI_NUM': None}
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{'Code': '176100', 'Text': 'SOLID STATE PHYSICS'}
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1986&All=true', 'xml': '8617823.xml'}