Electro-Optronic Gas Surface Translation Device
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DEVELOPER NOTE: "Electro-Optronic Gas" is interpreted as a Spin-Polarized Exciton-Polariton Gas. This is a quantum gas formed when excitons (electron-hole pairs) are strongly coupled with photons (light) in a microcavity. It is created by an external pump laser.
TOP-DOWN SCHEMATIC WITH RF TIMING OVERLAY (ASCII REFERENCE)
[Optical Pump Input (Laser)] [Ohmic 1..4]
╔═══════════════════════════════════════════════════════════════╗
║ ┌───────────────────────────────────────────────────────┐ ║
║ │ ← Direction of Polariton Gas Flow │ ║
║ │ ┌──────────── Pump / RF Section ────────────────┐ │ ║
║ │ │ G1 (0°) G2 (120°) G3 (240°) │ │ ║
║ │ │ ┌───────┐ ┌───────┐ ┌───────┐ │ │ ║
║ │ │ │ G1 │ │ G2 │ │ G3 │ │ │ ║
║ │ │ └───────┘ └───────┘ └───────┘ │ │ ║
║ │ └───────────────────────────────────────────────┘ │ ║
║ │ [Optical Gate 1] [Optical Gate 2] │ ║
║ │ █████████ (SLED zone) │ ║
║ │ █ SLED █ │ ║
║ │ █████████ │ ║
║ │ [Detector 1] [Detector 2] │ ║
║ └───────────────────────────────────────────────────────┘ ║
╚═══════════════════════════════════════════════════════════════╝
Timing (qualitative):
G1: sin(ωt + 0°)
G2: sin(ωt + 120°)
G3: sin(ωt + 240°)
Traveling potential along channel: G1 → G2 → G3
Fig 1. Schematic of the Polariton-Gas Propulsion Drive.
RF DRIVE SPECIFICATIONS
| Waveform | Sine, 3 phases (0°, 120°, 240°) |
|---|---|
| Frequency | 10–100 MHz (tuned for gas velocity) |
| Amplitude | 0.20–0.50 Vpp at gate |
| Impedance | 50 Ω lines; cold attenuation as needed |
| Feedback | Lock polariton density via optical detectors; adjust laser power |
CONCEPT AND OBJECTIVE
Goal: Demonstrate directional surface translation driven by a "surfed" quantum gas.
Principle:
- A circularly polarized pump laser creates a spin-polarized exciton-polariton gas.
- The tri-phase traveling gate potential (G1→G2→G3) creates a moving potential landscape via the Quantum Confined Stark Effect (QCSE).
- This "surfboards" the coherent polariton gas, forcing it to flow at high speed.
- This high-speed moving spin-current generates a localized magnetic field, which exerts a Lorentz force on the magnetic Fe sled.
Scope: Micro-sled motion on-chip at cryogenic temperatures (B-field not required).
ARCHITECTURE AND LAYOUT
Platform: III-V Semiconductor Microcavity
- Stack: Bottom DBR Mirror (AlAs/GaAs) / GaAs Quantum Wells / Top DBR Mirror
- Contacts: Al-based ohmics (for gates)
- Gates: Al on ALD Al2O3
- Sled: Pure Fe micro-sled, 200–300 nm thick
- Optical Access: A window in the top gates/wiring is required for the pump laser.
OPERATING CONDITIONS AND TARGETS
| B-field | 0 T (A major advantage over the QHE design) |
|---|---|
| Temp | 4.2 K (or 77 K with GaN-based materials) |
| Pump Laser | ~1.5-1.6 eV continuous-wave, circularly polarized |
| Polariton Density | 1010 - 1011 cm-2 |
| Gate drive | 0.20–0.50 Vpp, 10–100 MHz, 0°/120°/240° |
| Polariton Gas Velocity | 1,000–10,000 m/s (set by RF frequency) |
| Force | ~pN-nN scale (magnetic spin-current interaction) |
| Sled Velocity | 1–100 µm/s |
RISKS AND MITIGATION
- RF Heating: Lower Vpp, cold attenuators, pulsed drive.
- Sled Stiction: Smoother spacer, smaller contact area.
- Optical Heating: The pump laser adds heat. Mitigation: Use resonant pumping, optimize cavity Q-factor to lower the power threshold.
- Polariton Lifetime: The gas "evaporates" (decays) in picoseconds-to-nanoseconds. Mitigation: The gas must be moved to the sled *faster* than it decays. High-speed RF drive (MHz-GHz) is essential.
FORCE CALCULATION (SPIN-CURRENT OPTION)
Given:
- Polariton Gas Velocity (v): 10⁴ m/s (driven by RF)
- Polariton Density (n): 10¹¹ cm⁻² = 10¹⁵ m⁻²
- Channel Width (w): 5 µm
- Spin per polariton (S): S = ħ (assumed 100% circular polarization)
- Spin-Magnetic Moment (µ_S): µ_S ≈ µ_B (Bohr magneton)
1. Spin Current (I_S):
- I_S = (Flux of particles) × (Spin per particle)
- I_S = (n × v × w) × S
- I_S = (10¹⁵ m⁻²) × (10⁴ m/s) × (5 × 10⁻⁶ m) × ħ
- I_S ≈ 5 × 10¹³ (spins/s)
2. Force on Sled (Gradient Force):
- Sled Moment (m_sled) ≈ 7.34 × 10⁻¹¹ A·m² (from original doc)
- Force F ≈ m_sled × ∇B_gas
- The field B_gas from the tiny gas packet is extremely small.
- Force ≈ piconewton (pN) scale.
Implication:
- The force is *much smaller* than the original QHE design (which used a 1 µA *charge* current).
- Conclusion: This design is scientifically elegant and removes the need for a large B-field, but the propulsive force is significantly weaker. It is better suited as a "quantum fluid" sensor or transistor than a propulsion drive.
Topological Spin-Wave Translation Device
(Bismuth Telluride Quantum Transistor)
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DEVELOPER NOTE: This is a refactor of the "Graphene Plasmon" concept. The graphene channel is replaced by a Topological Insulator (TI), specifically Bismuth Telluride ($Bi_2Te_3$). This material functions as a "signalling medium" for a quantum transistor, leveraging its spin-momentum locked surface states at room temperature.
TOP-DOWN SCHEMATIC WITH RF PHASING OVERLAY (ASCII REFERENCE)
[Source (Ohmic)] [RF Phased Input] [Drain (Ferromagnet)]
╔═══════════════════════════════════════════════════════════════╗
║ ┌───────────────────────────────────────────────────────┐ ║
║ │ ← Direction of Spin-Current (Pump-dependent) │ ║
║ │ ┌────────── RF Phased-Gate Section ─────────────┐ │ ║
║ │ │ G1 (0°) G2 (120°) G3 (240°) │ │ ║
║ │ │ ┌───────┐ ┌───────┐ ┌───────┐ │ │ ║
║ │ │ │ G1 │ │ G2 │ │ G3 │ │ │ ║
║ │ │ └───────┘ └───────┘ └───────┘ │ │ ║
║ │ └───────────────────────────────────────────────┘ │ ║
║ │ │ ║
║ │ ███████████████████████████████████████████████████ │ ║
║ │ █ Bi-Te Topological Insulator Channel (Signalling Medium) █ │ ║
║ │ ███████████████████████████████████████████████████ │ ║
║ │ │ ║
║ └───────────────────────────────────────────────────────┘ ║
╚═══════════════════════════════════════════════════════════════╝
Phasing (qualitative):
G1: sin(ωt + 0°)
G2: sin(ωt + 120°)
G3: sin(ωt + 240°)
Traveling potential pump: G1 → G2 → G3
Fig 1. Schematic of the Phased-Drive Spin Transistor.
RF DRIVE SPECIFICATIONS
| Waveform | Sine, 3 phases (0°, 120°, 240°) |
|---|---|
| Frequency | 10–100 MHz (tuned for electron drift) |
| Amplitude | 0.10–0.20 Vpp at gate |
| Impedance | 50 Ω lines; requires matching network |
| Feedback | Lock output spin-current via Drain sensor; adjust RF amplitude/phase |
CONCEPT AND OBJECTIVE
Goal: Demonstrate a functional, directional, room-temperature **spin-transistor** using a phased-RF drive.
Principle:
- The $Bi_2Te_3$ channel has topological surface states (TSS). Due to **spin-momentum locking**, electrons moving "forward" (e.g., left-to-right) must have one spin (e.g., "up"), and electrons moving "backward" must have the opposite spin ("down").
- The phased RF gates act as a "peristaltic pump," forcing unpolarized electrons from the Source to move in a specific direction.
- As the electrons are forced to move, the $Bi_2Te_3$ *automatically polarizes them*. Pumping G1→G2→G3 creates a 100% "up" spin-current. Reversing the phase (G3→G2→G1) creates a 100% "down" spin-current.
- The Ferromagnetic Drain acts as a spin-detector. Its resistance is **LOW** for parallel spins (e.g., "up" spins) and **HIGH** for anti-parallel spins ("down" spins).
Transistor Action: The RF phase is the **Gate** signal. The output resistance is the **Drain** signal. By changing the RF phase rotation, we flip the output from a **LOW-R (ON)** state to a **HIGH-R (OFF)** state. This is a true spin transistor.
ARCHITECTURE AND LAYOUT
Platform: Topological Insulator on Si
- Channel: Thin-film $Bi_2Te_3$ (e.g., via MBE or PVD) on Si/SiO2.
- Gates: Al or Cu on ALD Al2O3.
- Contacts:
- Source: Ohmic contact (e.g., Ti/Au) to inject unpolarized electrons.
- Drain: Ferromagnetic contact (e.g., Fe/Co) to act as a spin-detector.
OPERATING CONDITIONS AND TARGETS
| B-field | 0 T (Required for topological protection) |
|---|---|
| Temp | 300 K (Room Temperature) |
| Gate drive | 0.10–0.20 Vpp, 10–100 MHz, 0°/120°/240° |
| Output Signal | Spin-Polarized Current (µA scale) |
| Output Metric | Magnetoresistance Ratio (ON/OFF) |
RISKS AND MITIGATION
- Bulk-Channel Shunting: At room temp, the "insulating" bulk of $Bi_2Te_3$ can become conductive, allowing unpolarized electrons to "leak" to the drain, washing out the signal. Mitigation: Use ultra-thin films; chemical doping (e.g., with Sb) to perfectly position the Fermi level in the bulk gap.
- Interface Spin-Flipping: The spin-polarized signal can be lost if electrons scatter at the $Bi_2Te_3$/gate interface. Mitigation: Use a high-quality hBN encapsulation layer to protect the surface state.
- Detector Efficiency: The ferromagnetic drain's ability to distinguish "up" vs. "down" spins is not 100%. Mitigation: Requires careful engineering of the $Bi_2Te_3$/Fe interface to maximize spin-detection efficiency.
TRANSISTOR PERFORMANCE (CALCULATION)
Concept:
The RF pump drives a charge current (I_charge). Spin-momentum locking
converts this to a pure spin-current (I_s). The ferromagnetic
detector's resistance changes based on the spin direction.
Given:
- Pumped Charge Current (I_charge) ≈ 1.0 µA
- Detector Efficiency (η): 40% (Typical for Fe/Co at 300K)
(This is the (R_high - R_low) / R_low ratio)
1. "ON" State (e.g., Forward Phase: G1→G2→G3)
- Pump forces electrons "forward".
- Spin-Momentum Locking → All electrons become Spin "Up".
- Detector is magnetized "Up" (Parallel).
- Resistance is LOW (R_low).
- Output Current I_out ≈ 1.0 µA.
2. "OFF" State (e.g., Reverse Phase: G3→G2→G1)
- Pump forces electrons "backward".
- Spin-Momentum Locking → All electrons become Spin "Down".
- Detector is magnetized "Up" (Anti-Parallel).
- Resistance is HIGH (R_high = R_low * (1 + η)).
- R_high = R_low * 1.4
- Output Current I_out ≈ 1.0 µA / 1.4 ≈ 0.71 µA.
Implication:
- By reversing the RF phasing, we modulate the output current between
1.0 µA (ON) and 0.71 µA (OFF).
- This is a functional, room-temperature, B-field-free spin transistor
controlled by RF phase. This is a direct "signal translation"
from an AC phase signal to a DC amplitude signal.
Graphene Plasmon-Wave Transistor (Plas-FET)
(Room-Temperature, B-Field-Free Operation)
#Shouts to Copilot and associated AI deliverance for this beautiful concept, lets make RF signalling dangerously fast!
DEVELOPER NOTE: This is a refactor of the "Plasmon Propulsion" concept. The device is now framed as a transistor, where the "plasmon sheeting" acts as the signal-carrying medium, analogous to electrons in a normal FET.
TOP-DOWN SCHEMATIC - PLASMON FIELD-EFFECT TRANSISTOR (Plas-FET)
[SOURCE: Phased-RF Input] [GATE: DC Bias] [DRAIN: Detector Output]
╔═══════════════════════════════════════════════════════════════╗
║ ┌───────────────────────────────────────────────────────┐ ║
║ │ ← Plasmon Wave Propagation (Source-to-Drain) │ ║
║ │ ┌────────── Plasmon Source ───────────┐ │ ║
║ │ │ G1 (0°) G2 (120°) G3 (240°) │ CONTROL PLASMON │ ║
║ │ │ ┌───────┐ ┌───────┐ ┌───────┐ │ ┌───────┐ ┌───────┐ │ ║
║ │ │ │ G1 │ │ G2 │ │ G3 │ │ │ GATE │ │ DRAIN │ │ ║
║ │ │ └───────┘ └───────┘ └───────┘ │ └───────┘ └───────┘ │ ║
║ │ └─────────────────────────────────┘ │ ║
║ │ │ ║
║ │ ███████████████████████████████████████████████████ │ ║
║ │ █ Graphene Plasmon Channel (2DEG) █ │ ║
║ │ ███████████████████████████████████████████████████ │ ║
║ └───────────────────────────────────────────────────────┘ ║
╚═══════════════════════════════════════════════════════════════╝
Phased Source Timing:
G1: sin(ωt + 0°)
G2: sin(ωt + 120°)
G3: sin(ωt + 240°)
Function: Phased gates (G1-G3) launch a plasmon wave. Control Gate
voltage modulates its transmission to the Drain.
Fig 1. Schematic of the Graphene Plasmon-Wave Transistor.
MICROWAVE DRIVE (SOURCE) SPECIFICATIONS
| Waveform | Sine, 3 phases (0°, 120°, 240°) to launch wave |
|---|---|
| Frequency | 1–10 GHz (Microwave, tuned for plasmon wavelength) |
| Amplitude | 0.10–0.20 Vpp at gate |
| Impedance | 50 Ω lines; requires microwave matching network |
CONCEPT AND OBJECTIVE
Goal: Elucidate a functional, room-temperature, high-frequency **Field-Effect Transistor (FET)** where the signal-carrying medium is a graphene plasmon wave, not a DC electron current.
Principle (Transistor Elucidation):
- SOURCE: The phased microwave gates (G1-G3) act as a launcher, "shooting" a continuous, unidirectional plasmon wave down the graphene channel.
- SIGNAL: This traveling plasmon wave *is* the signal, analogous to the electron flow from Source to Drain in a normal transistor.
- GATE: A separate DC-biased Control Gate is placed over the channel, between the Source and Drain. The voltage on this gate ($V_G$) is the transistor's input.
- TRANSISTOR ACTION:
- $V_G$ changes the electron density ($n_0$) in the graphene *under* the gate.
- This change in $n_0$ alters the plasmon's "refractive index" or impedance ($Z_p$) in that small region.
- ON-STATE ($V_G$ = $V_{on}$): The impedance of the gate region ($Z_{gate}$) matches the channel ($Z_{ch}$). The plasmon wave transmits freely to the Drain.
- OFF-STATE ($V_G$ = $V_{off}$): A large impedance mismatch ($Z_{gate} \neq Z_{ch}$) is created. The plasmon wave is **reflected** from the gate and cannot reach the Drain.
- DRAIN: A detector (e.g., a Schottky diode or bolometer) measures the *power* of the transmitted plasmon wave.
Scope: A room-temperature, GHz-speed switch for plasmonic and RF-photonic circuits.
ARCHITECTURE AND LAYOUT
Platform: Graphene-on-Substrate
- Stack: CVD Graphene encapsulated in hexagonal Boron Nitride (hBN) for high mobility (low plasmon damping).
- Source Gates (G1-G3): Al or Cu, designed as an interdigitated antenna for efficient plasmon launching.
- Control Gate: Al or Cu on a thin (5-10 nm) ALD Al2O3 dielectric.
- Drain Detector: Graphene P-N junction or Schottky-barrier detector.
OPERATING CONDITIONS AND TARGETS
| B-field | 0 T |
|---|---|
| Temp | 300 K (Room Temperature) |
| Graphene Density | $n_0 \approx 10^{12} \text{ cm}^{-2}$ (set by back-gate) |
| Gate (Source) Drive | 0.10–0.20 Vpp, 1–10 GHz, 0°/120°/240° |
| Gate (Control) Drive | DC Voltage (e.g., -2V to +2V) |
| Output Signal | Transmitted Plasmon Power (S21) |
| Target Metric | ON/OFF Ratio > 10 dB |
RISKS AND MITIGATION
- Plasmon Damping: At room temp, plasmons decay quickly. Mitigation: Use high-quality hBN-encapsulated graphene, which dramatically increases plasmon lifetime.
- Insertion Loss: The phased-gate launcher (Source) is inefficient and may not launch plasmons well. Mitigation: Careful antenna/coupler design is critical.
- Gate Leakage: The DC Control Gate might leak current, ruining the FET action. Mitigation: High-quality, pinhole-free Al2O3 or hBN gate dielectric.
- Impedance Mismatch: Matching 50 Ω microwave lines to the high-impedance plasmon channel is difficult. Mitigation: On-chip matching networks.
TRANSISTOR PERFORMANCE (CONCEPTUAL)
Concept:
The Control Gate modulates the plasmon wave vector ($k_p$),
which is dependent on carrier density ($n_0$).
$k_p \propto \sqrt{\omega / n_0}$ (simplified).
A change in $k_p$ creates an impedance mismatch, causing reflection.
Given:
- Channel Density (n_ch): $1 \times 10^{12} \text{ cm}^{-2}$
- Gated Density (n_gate): Modulated by $V_G$
1. ON-STATE ($V_G \approx V_{on}$):
- $V_G$ set so that $n_{gate} \approx n_{ch}$.
- Wave vector $k_p(\text{gate}) \approx k_p(\text{channel})$.
- Impedance is matched.
- Plasmon wave transmits freely.
- Transmission (S21) ≈ -3 dB (standard insertion loss).
2. OFF-STATE ($V_G \approx V_{off}$):
- $V_G$ set to deplete the channel, e.g., $n_{gate} \approx 0.2 \times 10^{12} \text{ cm}^{-2}$.
- $k_p(\text{gate})$ is now $\approx 2.2\times$ larger than $k_p(\text{channel})$.
- This large, abrupt change in $k_p$ acts like a mirror.
- Most of the plasmon wave is reflected.
- Transmission (S21) ≈ -20 dB.
Implication:
- The device demonstrates a clear ON/OFF ratio.
- ON/OFF Ratio = (-3 dB) - (-20 dB) = 17 dB.
- Conclusion: This is a viable, high-speed (GHz) transistor
where the signal ("plasmon sheeting") is controlled by a
static gate voltage, elucidating its function as an RF switch.
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