Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

TheoryofInducing Electron SpinCoherence Without SpinPrecession in GaAsQuantumWellWaveguides

N. H. KwongandR, Susanta K. Sarkar, Phedon Palinginis

Published Jan 1, 2005• 0 citations
OpenAlex

Abstract

Wepresent atheory foradifferential transmission experiment that generated electron spin coherence inquantum wellwaveguides without DCmagnetic fields. We showhowoptical selection rules explain thespin coherence's creation anddetection. 02004Optical Society ofAmerica OCIScodes: (190.5970) Semiconductor nonlinear optics including MQW;(300.6470) Spectroscopy, semiconductors Thedemonstration oflong-lived electron spin coherence atroomtemperature insemiconductors (1)hasenhanced theprospects ofusing coherent spin manipulation inoptoelectronics andhence hasdrawnmuchrecent research effort tothis area. Inmostexperiments, theelectron spin coherence wasdemonstrated bydetecting thespin's precession ineither anexternally applied DCmagnetic field oraninternal magnetic field induced bymagnetic ion (Mn)doping orstrain innonmagnetic materials (2). Recently theexperimental group inthis collaboration (Oregon) reported theobservation ofelectron spin coherence inGaAsquantum wells without thehelp ofmagnetic fields, external orinternal (3). Wepresent here atheoretical analysis ofthephysical processes contributing tothecreation anddetection ofthis spin coherence. A simple model, based mainly onoptical selection rules, gives aresonance structure atthespectral position ofanexperimentally observed peak inthedifferential transmission (DT)spectrum. Itsupports theinterpretation oftheobserved DTpeak asbeing duetoelectron spin coherence intheabsence ofany DCmagnetic field. Wealso calculate theDTinthepresence ofanexternal DCmagnetic field. Inthis case, wefind theconventional Zeemansplitting (inagreement withtheexperiment). Thisrules outtheinterpretation ofthe observed peak interms ofpopulation pulsations (4). Ourexperiment useslight traveling along thequantum well's plane (waveguide geometry, seeFig. 1)toexcite a light-hole exciton theelectron ofwhich isinasuperposition ofbothspin states. Thesimplest version ofourtheory is afour-level model: twoconduction bandstates andtwolight-hole valence bandstates. Fig. 2shows theusual level schematic ofaGaAsquantum well. An electron inalight-hole orbital, e.g. jz=-1/2,canbeexcited byC+ polarized light tooneconduction bandspin orbital (sz=1/2)orbyz-polarized light toanother conduction band spin orbital (s5=-1/2). Underexcitation bylight ofbothpolarizations anelectron canbeexcited into the conduction bandinasuperposition ofthetwospin orbitals. Thisspin coherence cannotbecreated intheusual, normal incidence, geometry where thelight lacks thez-polarized component. Itcanbecreated inthewaveguide geometry adopted inourexperiment, where thelight's TM component isz-polarized andtheTEcomponent contains both circular polarizations. TM

Related papers

Inducing electron spincoherence inGaAsquantumwell waveguides: SpinCoherence without spinprecession

Phedon Palinginis, Pei-Cheng KuandConnie

Electron spin coherence isinduced vialight-hole transitions inaquantum well waveguide without aDC magnetic field. Thespincoherence isdetected through effects ofquantum interference inspectral domain nonlinear optical response. 02005 Optical Society ofAmerica OCIScodes: (190.5970) Semiconductor nonlinear optics including MQW;(300.6470) Spectroscopy, semiconductors Coherent spin manipulation plays animportant role inspin-based electronics andphotonics andinquantum information technologies (1). Inmostexperiments, coherent spin manipulation wascarried outinthepresence ofan external DC magnetic field that induces aZeemansplitting between theconduction bandelectron spin states. Coherent superposition ofthese spin states leads toaLarmor spin precession, which canbedetected with transient optical techniques. Coherent spin manipulation without external magnetic fields innon-magnetic semiconductors hasalso beendemonstrated inarecent study (2), inwhichaneffective internal magnetic field induced bystrain results inaspin splitting intheconduction band. Here, wereport experimental demonstration ofinducing anddetecting electron spincoherence inaGaAs quantum well(QW)without theuseofeither anexternal oreffective internal magnetic field. We havetaken advantage ofthespin-orbit coupling inthevalence bandandhaveusedlight-hole (LH)transitions inwaveguide geometry toinduce electron spincoherence. Intheabsence ofspin precession, theinduced spincoherence is detected through quantum interference inthespectral domain, instead oftimedomain, coherent nonlinear optical response. (a)

•Jan 1, 2005•0 citations

Theory of inducing electron spin coherence without spin precession in GaAs quantum well waveguides

N. H. Kwong, Rudolf H. Binder

We present a theory for a differential transmission experiment that generated electron spin coherence in quantum well waveguides without DC magnetic fields. We show how optical selection rules explain the spin coherence's creation and detection.

Quantum Electronics and Laser Science Conference•Dec 10, 2005•0 citations

Electromagnetically induced transparency viaelectron spin coherence in a quantum wellwaveguide

Tao Li, Hailin Wang, N. H. Kwong +1 more

We propose and analyze a novel scheme to realize electromagnetically induced transparency (EIT) via robust electron spin coherence in semiconductor quantum wells. This scheme uses light hole transitions in a quantum well waveguide to induce electron spin coherence in the absence of an external magnetic field. For certain polarization configurations, the light hole transitions form a crossed double-V system. EIT in this system is strongly modified by a coherent wave mixing process induced by the electron spin coherence.

Optics Express•Dec 1, 2003•47 citations

Inducing electron spin coherence in GaAs quantum well waveguides: Spin coherence without spin precession

Susanta Sarkar, Phedon Palinginis, C. C. Kuo +4 more

We demonstrate the generation and detection of electron spin coherence in a quantum well waveguide without either an external or internal dc magnetic field. In the absence of spin precession, the induced spin coherence is detected through effects of quantum interference in the spectral domain coherent nonlinear optical response. We interpret the experimental results qualitatively using a few-level model with optical selection rules as its basic ingredient.

arXiv:cond-mat/0410221•Physical Review B•Jul 20, 2005•21 citations

Optically Stimulated andSpontaneously Generated Electron SpinCoherence inQuantuin Dots

Guy Lewis Steel, A. S. Bracker, J. Sham +1 more

Wereport theobservation oflong-lived quantum beats inquantum dots(ensemble andsingle) duetoelectron spincoherence, resulting fromstimulated Ramantransition aswell asspontaneous radiative decay ofthetrion state. © 2004Optical Society ofAmerica OCIScodes:(300.6240) Coherent transient spectroscopy; (300.6420) Nonlinear spectroscopy; (300.6470) Semi- conductors spectroscopy Theelectron spininquantumdots(QD's) isapromising candidate foraqubit forquantuminformation processing duetoitslonglifetime andanticipated robust coherence (1). Suchstructures havefeatured in numerous proposals using ultrafast optical coupling tocoherently manipulate thespinstates. Inthis paper, wedemonstrate suchcoupling andfindanewcontribution tothecoherence observed through quantum beats.

•Jan 1, 2005•0 citations

Electromagnetically induced transparency in semiconductors

Hailin Wang

This final technical report summarizes research supported by ARO in two areas: electromagnetically induced transparency (EIT) from electron spin coherence and cavity QED with nitrogen vacancy (NV) centers in diamond nanocrystals. We have developed three different schemes to realize EIT using electron spin coherence in semiconductor quantum wells. The three schemes include the use of V-type three-level systems via heavy hole excitonic transitions in an external magnetic field in the Voigt geometry, the use of V-type three-level systems via light hole excitonic transitions in a waveguide geometry and in the absence of an external magnetic field, and the use of a lamda-type three-level system in a mixed-type quantum well structure. We have achieved the breakthrough of realizing the strong coupling regime in cavity QED by coupling NV centers in diamond nanocrystals to whispering gallery modes in a deformed fused silica microsphere. In addition, our improved understanding on how electron spin coherence contributes to nonlinear optical processes in semiconductors has also led to the demonstration of a spin manipulation scheme that controls both the amplitude and phase of electron spin precessions.

•Jun 1, 2006•0 citations
Wepresent atheory foradifferential transmission experiment that generated electron spin coherence inquantum wellwaveguides without DCmagnetic fields. We showhowoptical selection rules explain thespin coherence's creation anddetection. 02004Optical Society ofAmerica OCIScodes: (190.5970) Semiconductor nonlinear optics including MQW;(300.6470) Spectroscopy, semiconductors Thedemonstration oflong-lived electron spin coherence atroomtemperature insemiconductors (1)hasenhanced theprospects ofusing coherent spin manipulation inoptoelectronics andhence hasdrawnmuchrecent research effort tothis area. Inmostexperiments, theelectron spin coherence wasdemonstrated bydetecting thespin's precession ineither anexternally applied DCmagnetic field oraninternal magnetic field induced bymagnetic ion (Mn)doping orstrain innonmagnetic materials (2). Recently theexperimental group inthis collaboration (Oregon) reported theobservation ofelectron spin coherence inGaAsquantum wells without thehelp ofmagnetic fields, external orinternal (3). Wepresent here atheoretical analysis ofthephysical processes contributing tothecreation anddetection ofthis spin coherence. A simple model, based mainly onoptical selection rules, gives aresonance structure atthespectral position ofanexperimentally observed peak inthedifferential transmission (DT)spectrum. Itsupports theinterpretation oftheobserved DTpeak asbeing duetoelectron spin coherence intheabsence ofany DCmagnetic field. Wealso calculate theDTinthepresence ofanexternal DCmagnetic field. Inthis case, wefind theconventional Zeemansplitting (inagreement withtheexperiment). Thisrules outtheinterpretation ofthe observed peak interms ofpopulation pulsations (4). Ourexperiment useslight traveling along thequantum well's plane (waveguide geometry, seeFig. 1)toexcite a light-hole exciton theelectron ofwhich isinasuperposition ofbothspin states. Thesimplest version ofourtheory is afour-level model: twoconduction bandstates andtwolight-hole valence bandstates. Fig. 2shows theusual level schematic ofaGaAsquantum well. An electron inalight-hole orbital, e.g. jz=-1/2,canbeexcited byC+ polarized light tooneconduction bandspin orbital (sz=1/2)orbyz-polarized light toanother conduction band spin orbital (s5=-1/2). Underexcitation bylight ofbothpolarizations anelectron canbeexcited into the conduction bandinasuperposition ofthetwospin orbitals. Thisspin coherence cannotbecreated intheusual, normal incidence, geometry where thelight lacks thez-polarized component. Itcanbecreated inthewaveguide geometry adopted inourexperiment, where thelight's TM component isz-polarized andtheTEcomponent contains both circular polarizations. TM
Electron spin coherence isinduced vialight-hole transitions inaquantum well waveguide without aDC magnetic field. Thespincoherence isdetected through effects ofquantum interference inspectral domain nonlinear optical response. 02005 Optical Society ofAmerica OCIScodes: (190.5970) Semiconductor nonlinear optics including MQW;(300.6470) Spectroscopy, semiconductors Coherent spin manipulation plays animportant role inspin-based electronics andphotonics andinquantum information technologies (1). Inmostexperiments, coherent spin manipulation wascarried outinthepresence ofan external DC magnetic field that induces aZeemansplitting between theconduction bandelectron spin states. Coherent superposition ofthese spin states leads toaLarmor spin precession, which canbedetected with transient optical techniques. Coherent spin manipulation without external magnetic fields innon-magnetic semiconductors hasalso beendemonstrated inarecent study (2), inwhichaneffective internal magnetic field induced bystrain results inaspin splitting intheconduction band. Here, wereport experimental demonstration ofinducing anddetecting electron spincoherence inaGaAs quantum well(QW)without theuseofeither anexternal oreffective internal magnetic field. We havetaken advantage ofthespin-orbit coupling inthevalence bandandhaveusedlight-hole (LH)transitions inwaveguide geometry toinduce electron spincoherence. Intheabsence ofspin precession, theinduced spincoherence is detected through quantum interference inthespectral domain, instead oftimedomain, coherent nonlinear optical response. (a)
We propose and analyze a novel scheme to realize electromagnetically induced transparency (EIT) via robust electron spin coherence in semiconductor quantum wells. This scheme uses light hole transitions in a quantum well waveguide to induce electron spin coherence in the absence of an external magnetic field. For certain polarization configurations, the light hole transitions form a crossed double-V system. EIT in this system is strongly modified by a coherent wave mixing process induced by the electron spin coherence.
Wereport theobservation oflong-lived quantum beats inquantum dots(ensemble andsingle) duetoelectron spincoherence, resulting fromstimulated Ramantransition aswell asspontaneous radiative decay ofthetrion state. © 2004Optical Society ofAmerica OCIScodes:(300.6240) Coherent transient spectroscopy; (300.6420) Nonlinear spectroscopy; (300.6470) Semi- conductors spectroscopy Theelectron spininquantumdots(QD's) isapromising candidate foraqubit forquantuminformation processing duetoitslonglifetime andanticipated robust coherence (1). Suchstructures havefeatured in numerous proposals using ultrafast optical coupling tocoherently manipulate thespinstates. Inthis paper, wedemonstrate suchcoupling andfindanewcontribution tothecoherence observed through quantum beats.
This final technical report summarizes research supported by ARO in two areas: electromagnetically induced transparency (EIT) from electron spin coherence and cavity QED with nitrogen vacancy (NV) centers in diamond nanocrystals. We have developed three different schemes to realize EIT using electron spin coherence in semiconductor quantum wells. The three schemes include the use of V-type three-level systems via heavy hole excitonic transitions in an external magnetic field in the Voigt geometry, the use of V-type three-level systems via light hole excitonic transitions in a waveguide geometry and in the absence of an external magnetic field, and the use of a lamda-type three-level system in a mixed-type quantum well structure. We have achieved the breakthrough of realizing the strong coupling regime in cavity QED by coupling NV centers in diamond nanocrystals to whispering gallery modes in a deformed fused silica microsphere. In addition, our improved understanding on how electron spin coherence contributes to nonlinear optical processes in semiconductors has also led to the demonstration of a spin manipulation scheme that controls both the amplitude and phase of electron spin precessions.