Study and control of coherent excited state relaxation in nPc and single wall carbon nanotube

We study quantum optical properties of the single-walled carbon nanotube (SWCNT) by introducing the effective interaction between the quantized electromagnetic field and the confined electrons in the SWCNT. Our purpose is to explore the quantum natures of electron transport in the SWCNT by probing its various quantum optical properties relevant to quantum coherence, such as the interference of the scattered and emitted photons, and the bunching and anti-bunching of photons which are characterized by the higher order coherence functions. In the strong field limit, we study the interband Rabi oscillation of electrons driven by a classical light. We also investigate the possible lasing mechanism in superradiation of coherent electrons in a SWCNT driven by a light pump or electron injection, which generate electron population inversion in the higher energy-band of SWCNT.We study quantum optical properties of the single-walled carbon nanotube (SWCNT) by introducing the effective interaction between the quantized electromagnetic field and the confined electrons in the SWCNT. Our purpose is to explore the quantum natures of electron transport in the SWCNT by probing its various quantum optical properties relevant to quantum coherence, such as the interference of the scattered and emitted photons, and the bunching and anti-bunching of photons which are characterized by the higher order coherence functions. In the strong field limit, we study the interband Rabi oscillation of electrons driven by a classical light. We also investigate the possible lasing mechanism in superradiation of coherent electrons in a SWCNT driven by a light pump or electron injection, which generate electron population inversion in the higher energy-band of SWCNT.

arXiv:0904.2231Apr 15, 20090 citations

Experimental straintronics in nanotube quantum dots

L. Huang, I. G. Rebollo, A. R. Champagne

Single-wall carbon nanotubes (SWCNTs) are narrow ribbons of graphene with atomically precise edges and a single quantum transport channel, at experimentally-relevant dopings. This makes them ideal systems to harness quantum transport straintronics (QTS), i.e. using mechanical strain to control accurately quantum transport. We present QTS data from three single-wall carbon nanotube quantum dot (SWCNT-QD) transistors over a broad range of in-situ tunable and reversible uniaxial strain ( $Δ\varepsilon_\text{mech}\approx$ 0 to 3 %). We first present the nanofabrication of the suspended SWCNT transistors whose channel lengths are $\approx$ 30 nm. The channels are strained by moving gold clamps holding firmly the nanotubes. We present detailed charge transport data, $dI/dV_{\text{B}} - V_{\text{B}} - V_{\text{G}}$ and $dI/dV_{\text{B}} - V_{\text{B}} - Δ\varepsilon_\text{mech}$ , showing a large mechanical-gating effect of the SWCNT-QDs. The precise reversibility of the data, and their agreement with QTS theory, confirms that the tubes are strained elastically. We demonstrate that the mechanical control of the QD doping is not due to capacitive-gating effects, but to quantitatively predictable bandstructure changes including a strain-tunable bandgap. This precise mechanical control of the doping and bandgap of SWCNT-QDs could find applications in qubits, condensed matter physics, and homojunction molecular transistors.Single-wall carbon nanotubes (SWCNTs) are narrow ribbons of graphene with atomically precise edges and a single quantum transport channel, at experimentally-relevant dopings. This makes them ideal systems to harness quantum transport straintronics (QTS), i.e. using mechanical strain to control accurately quantum transport. We present QTS data from three single-wall carbon nanotube quantum dot (SWCNT-QD) transistors over a broad range of in-situ tunable and reversible uniaxial strain ($Δ\varepsilon_\text{mech}\approx$ 0 to 3 %). We first present the nanofabrication of the suspended SWCNT transistors whose channel lengths are $\approx$ 30 nm. The channels are strained by moving gold clamps holding firmly the nanotubes. We present detailed charge transport data, $dI/dV_{\text{B}} - V_{\text{B}} - V_{\text{G}}$ and $dI/dV_{\text{B}} - V_{\text{B}} - Δ\varepsilon_\text{mech}$, showing a large mechanical-gating effect of the SWCNT-QDs. The precise reversibility of the data, and their agreement with QTS theory, confirms that the tubes are strained elastically. We demonstrate that the mechanical control of the QD doping is not due to capacitive-gating effects, but to quantitatively predictable bandstructure changes including a strain-tunable bandgap. This precise mechanical control of the doping and bandgap of SWCNT-QDs could find applications in qubits, condensed matter physics, and homojunction molecular transistors.

cond-mat.mes-hallCross-listedarXiv:2606.12180Jun 11, 2026

Δ\varepsilon_\text{mech}\approx

0 to 3 %). We first present the nanofabrication of the suspended SWCNT transistors whose channel lengths are

\approx

30 nm. The channels are strained by moving gold clamps holding firmly the nanotubes. We present detailed charge transport data,

dI/dV_{\text{B}} - V_{\text{B}} - V_{\text{G}}

and

dI/dV_{\text{B}} - V_{\text{B}} - Δ\varepsilon_\text{mech}

, showing a large mechanical-gating effect of the SWCNT-QDs. The precise reversibility of the data, and their agreement with QTS theory, confirms that the tubes are strained elastically. We demonstrate that the mechanical control of the QD doping is not due to capacitive-gating effects, but to quantitatively predictable bandstructure changes including a strain-tunable bandgap. This precise mechanical control of the doping and bandgap of SWCNT-QDs could find applications in qubits, condensed matter physics, and homojunction molecular transistors.