Quantum-Memory-Enabled Ultrafast Optical Switching in Carbon Nanotubes

Abstract

Optical nonlinearities can be engineered into high-speed optical gates when a probe signal is switched coherently and fast by an optical control pulse through various nonlinear effects for switching. In semiconductors, a strong light–matter interaction can also excite many electrons to interact with each other, which can deteriorate switching through Coulomb-induced dephasing. Here, we demonstrate that optical transmission of carbon nanotubes can be switched reversibly hundreds of times via detuned Rabi splitting, faster than 200 fs via nonresonant but strong control pulses. Our detailed experiment–theory analysis identifies that quantum memory in Coulombic scattering restores reversibility while simultaneously reducing undesirable pure dephasing of coherences. This capability creates new possibilities for ultrafast quantum optoelectronic processing in quantum materials.

Exciton‐Dominated Ultrafast Optical Response in Atomically Thin PtSe2

“…[6][7][8][9][10][11][12][13] Also, ultrafast light-matter interactions can modulate excitons, enabling novel quantum memory and switching effects. [14][15][16][17][18][19] Therefore, understanding exciton behaviors on Strongly bound excitons are a characteristic hallmark of 2D semiconductors, enabling unique light-matter interactions and novel optical applications. Platinum diselenide (PtSe 2 ) is an emerging 2D material with outstanding optical and electrical properties and excellent air stability.…”

Ultrafast Photo‐Thermal Switching of Terahertz Spin Currents

“…The discovery of laser‐induced ultrafast demagnetization [ 1 ] provides a perfect platform to manipulate spins at sub‐picosecond timescales and opens up a promising route to develop future information technology [ 2–4 ] at terahertz speed. [ 5,6 ] This intriguing observation revolutionized the field [ 7–10 ] of terahertz sources by achieving high bandwidth emission at low‐cost and highly simplified fabrication approaches.…”

Characteristics of ultrafast response induced by impulsive interference of excitons in a GaAs/AlAs multiple quantum well on a slightly strained buffer layer

“…The incompatibility between the strong optical nonlinearity and the ultrafast carrier/ exciton lifetime has been an important topic, and numerous types of investigations have been carried out to overcome it. For example, switching based on intraband carrier dynamics, 1,2) gain dynamics, 3,4) detuned Rabi splitting, 5) twophoton absorption, 6) photonic crystals, [7][8][9] metamaterials, 10) and the plasmonic effect [11][12][13][14] can be used to reduce the response time.…”