Interactive visuals that explain what’s real and what’s hard across sensing, quantum networking, and computing.
How measurement time and bandwidth trade off in a quantum sensor. Model: SNR ≈ (Signal/NoiseDensity) × √(T / BW)
. Adjust assumptions to see regimes.
Interpretation: higher SNR means clearer detection. You can raise SNR by increasing signal, reducing noise density, widening integration time, or narrowing bandwidth — but bandwidth reduces temporal resolution.
Secret key rate vs distance using a simple DV‑QKD model. Channel loss ηch = 10^{−αL/10}
. Click prob p = μ ηdet ηch + p_dark
. QBER from dark counts. Rate ≈ sifted × secret fraction.
Interpretation: stronger detectors and lower loss push out the distance where key rate collapses; dark counts raise QBER and kill the secret fraction.
Surface‑code style back‑of‑envelope. Logical error per cycle: pL ≈ A (p / p_th)^{(d+1)/2}
with p_th ≈ 1%
, A ≈ 0.1
. Overhead ≈ N_phys ≈ 2 d²
per logical qubit. See feasibility vs physical error and code distance.
Interpretation: moving left/down (lower physical error, higher code distance) reduces logical error but increases overhead. The sweet spot is where pL beats the target at acceptable overhead.