Probing different regimes of strong field light–matter interaction with semiconductor quantum dots and few cavity photons

AbstractThrough the manipulation of metallic structures, light–matter interaction can enter into the realm of quantum mechanics. For example, intense terahertz pulses illuminating a metallic nanotip can promote terahertz field–driven electron tunneling to generate enormous electron emission currents in a subpicosecond time scale. By decreasing the dimension of the metallic structures down to the nanoscale and angstrom scale, one can obtain a strong field enhancement of the incoming terahertz field to achieve atomic field strength of the order of V/nm, driving electrons in the metal into tunneling regime by overcoming the potential barrier. Therefore, designing and optimizing the metal structure for high field enhancement are an essential step for studying the quantum phenomena with terahertz light. In this review, we present several types of metallic structures that can enhance the coupling of incoming terahertz pulses with the metals, leading to a strong modification of the potential barriers by the terahertz electric fields. Extreme nonlinear responses are expected, providing opportunities for the terahertz light for the strong light–matter interaction. Starting from a brief review about the terahertz field enhancement on the metallic structures, a few examples including metallic tips, dipole antenna, and metal nanogaps are introduced for boosting the quantum phenomena. The emerging techniques to control the electron tunneling driven by the terahertz pulse have a direct impact on the ultrafast science and on the realization of next-generation quantum devices.

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Quantum optics and cavity QED with quantum dots in photonic crystals

10.1093/oso/9780198768609.003.0008 ◽

2017 ◽

Author(s):

Jelena Vučković

Keyword(s):

Quantum Dots ◽

Information Processing ◽

Quantum Information ◽

Quantum Optics ◽

Quantum Electrodynamics ◽

Cavity Qed ◽

Cavity Quantum Electrodynamics ◽

Test Bed ◽

Matter Interaction ◽

Light Matter Interaction

Quantum dots in optical nanocavities are interesting as a test-bed for fundamental studies of light–matter interaction (cavity quantum electrodynamics, QED), as well as an integrated platform for information processing. As a result of the strong field localization inside sub-cubic-wavelength volumes, these dots enable very large emitter–field interaction strengths. In addition to their use in the study of new regimes of cavity QED, they can also be employed to build devices for quantum information processing, such as ultrafast quantum gates, non-classical light sources, and spin–photon interfaces. Beside quantum information systems, many classical information processing devices, such as lasers and modulators, benefit greatly from the enhanced light–matter interaction in such structures. This chapter gives an introduction to quantum dots, photonic crystal resonators, cavity QED, and quantum optics on this platform, as well as possible device applications.

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Lightwave-controlled electron dynamics in graphene

EPJ Web of Conferences ◽

10.1051/epjconf/201920505002 ◽

2019 ◽

Vol 205 ◽

pp. 05002

Author(s):

Christian Heide ◽

Takuya Higuchi ◽

Konrad Ullmann ◽

Heiko B. Weber ◽

Peter Hommelhoff

Keyword(s):

Strong Field ◽

Polarized Light ◽

Laser Pulses ◽

Weak Field ◽

Ultrashort Laser Pulses ◽

Electron Dynamics ◽

Matter Interaction ◽

Linearly Polarized ◽

Light Matter Interaction ◽

Optical Cycle

We demonstrate that currents induced in graphene by ultrashort laser pulses are sensitive to the exact shape of the electric-field waveform. By increasing the field strength, we found a transition of the light–matter interaction from the weak-field to the strong-field regime at around 2 V/nm, where intraband dynamics influence interband transitions. In this strong-field regime, the light-matter interaction can be described by the wavenumber trajectories of electrons in the reciprocal space. For linearly polarized light the electron dynamics are governed by repeated sub-optical-cycle Landau-Zener transitions between the valence- and conduction band, resulting in Landau-Zener-Stuckelberg interference, whereas for circular polarized light this interference is supressed.

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