This thesis presents optical methods to split the energy levels of electronic valleys in transition-metal dichalcogenides (TMDs) by means of coherent light-matter interactions. The electronic valleys found in monolayer TMDs such as MoS2, WS2, and WSe2 are among the many novel properties exhibited by semiconductors when thinned down to a few atomic layers, and have have been proposed as a new way to carry information in next generation devices (so-called valleytronics). These valleys are, however, normally locked in the same energy level, which limits their potential use for applications. The author describes experiments performed with a pump-probe technique using transient absorption spectroscopy on MoS2 and WS2. It is demonstrated that hybridizing the electronic valleys with light allows one to optically tune their energy levels in a controllable valley-selective manner. In particular, by using off-resonance circularly polarized light at small detuning, one can tune the energy level of one valley through the optical Stark effect. Also presented within are observations, at larger detuning, of a separate contribution from the so-called Bloch--Siegert effect, a delicate phenomenon that has eluded direct observation in solids. The two effects obey opposite selection rules, enabling one to separate the two effects at two different valleys.
| ISBN: | 9783319887999 |
| Publication date: | 4th September 2018 |
| Author: | Edbert Jarvis Sie |
| Publisher: | Springer an imprint of Springer International Publishing |
| Format: | Paperback |
| Pagination: | 129 pages |
| Series: | Springer Theses |
| Genres: |
Condensed matter physics (liquid state and solid state physics) Laser physics Spectrum analysis, spectrochemistry, mass spectrometry Engineering applications of electronic, magnetic, optical materials Electronic devices and materials Atomic and molecular physics |
This thesis presents optical methods to split the energy levels of electronic valleys in transition-metal dichalcogenides (TMDs) by means of coherent light-matter interactions. The electronic valleys found in monolayer TMDs such as MoS2, WS2, and WSe2 are among the many novel properties exhibited by semiconductors when thinned down to a few atomic layers, and have have been proposed as a new way to carry information in next generation devices (so-called valleytronics). These valleys are, however, normally locked in the same energy level, which limits their potential use for applications. The author describes experiments performed with a pump-probe technique using transient absorption spectroscopy on MoS2 and WS2. It is demonstrated that hybridizing the electronic valleys with light allows one to optically tune their energy levels in a controllable valley-selective manner. In particular, by using off-resonance circularly polarized light at small detuning, one can tune the energy level of one valley through the optical Stark effect. Also presented within are observations, at larger detuning, of a separate contribution from the so-called Bloch--Siegert effect, a delicate phenomenon that has eluded direct observation in solids. The two effects obey opposite selection rules, enabling one to separate the two effects at two different valleys.
Coherent Light-Matter Interactions in Monolayer Transition-Metal Dichalcogenides features in the following genres: Condensed matter physics (liquid state and solid state physics), Laser physics, Spectrum analysis, spectrochemistry, mass spectrometry, Engineering applications of electronic, magnetic, optical materials, Electronic devices and materials, Atomic and molecular physics
Coherent Light-Matter Interactions in Monolayer Transition-Metal Dichalcogenides is available in Paperback, Hardback
Coherent Light-Matter Interactions in Monolayer Transition-Metal Dichalcogenides was written by Edbert Jarvis Sie and published by Springer an imprint of Springer International Publishing
Coherent Light-Matter Interactions in Monolayer Transition-Metal Dichalcogenides has 129 pages
Yes it is part of Springer Theses series
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