SWCNT@MWCNT Photonic-Ternary Device

Overview

The foundational device patent covers three core inventions: metallocene CVD fabrication of the SWCNT@MWCNT structure, the photonic-to-ternary transducer architecture, and the AC switching method. The device consists of two concentric carbon nanotubes — a metallic (8,8) armchair single-walled nanotube inside a multi-walled nanotube — separated by a 0.34 nm van der Waals gap.

Trit encoding uses photon absorption combined with AC pulse polarity: a photon during the positive phase of the AC cycle produces trit +1, no photon produces a true zero (trit 0), and a photon during the negative phase produces trit −1. The device operates as a photonic-to-electrical transducer, not a traditional gate-controlled FET.

The MWCNT outer shell normally suppresses the SWCNT conductance through inter-wall quantum coupling. When a photon is absorbed by the MWCNT, its energy levels detune from the SWCNT, weakening the coupling and allowing current to flow. The AC terminal polarity then determines the direction — and therefore the trit value.

Key Innovations

• Two-layer SWCNT@MWCNT coaxial structure as a photonic-ternary transducer
• AC pulse polarity encoding for balanced ternary states (+1, 0, −1)
• Photon-gated conductance modulation via inter-wall coupling detuning
• Metallocene CVD fabrication yielding controlled chirality and diameter
• True zero state from absence of signal — no gate bias required
• Dual-photon mode enabling up to 12 distinguishable states per device

Technical Approach

The SWCNT is a metallic ballistic conductor functioning as a one-dimensional transmission line. Trits are AC pulse polarities on this transmission line, not DC gate-controlled carrier types. The three inputs — two photon wavelengths and an AC signal — are each independent and can each operate at their own clock rate.

In dual-photon mode, two photons at different wavelengths address the MWCNT gate and SWCNT signal independently. Combined with AC polarity, this yields 12 distinguishable states from a single device — wavelength-division multiplexing at the nanotube level.

Verification

The device was rigorously verified using non-equilibrium Green's function (NEGF) quantum transport simulation on 2 April 2026. The simulation confirms:

• Trit +1 current: +74 µA (photon + AC positive phase)
• Trit −1 current: −74 µA (photon + AC negative phase)
• Trit 0 noise floor: ~35 nA (no photon, true zero)
• Current symmetry I(+V)/I(−V): 1.0000 (perfect)
• Signal-to-noise ratio: >2000 (54 dB) — digital-grade switching
• MWCNT coupling detuning mechanism: simulation-verified

GW+BSE optical calculations verify the M₁₁ transition of the inner (8,8) SWCNT at 693 nm (1.79 eV) — the drive photon wavelength (λ₂). The outer MWCNT gate photon is λ₁ ≈ 1678 nm (E₂₂). The initial design estimate of 710 nm was refined to 693 nm by GW+BSE simulation (2.4% correction).

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