JTL Hop Lab

A Josephson Transmission Line regenerates the SFQ token at each stage (fresh area ≈ Φ₀) — it is not a passive CMOS wire. More stages ⇒ more delay, junctions, and bias. Fine JTL delay ≠ missing-epoch DFF pads.

JTL stages

τ per stage (ps, illustrative)

Myth mode: passive “wire” (no regeneration)

Stages

Delay ≈ n·τ

20 ps

Regenerations

Arrived?

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Last area

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Bucket brigade — each JJ stage remakes Φ₀ (or dies in myth mode)

Hop	Stage	Action	Area ≈	Status
Click “Launch pulse”. Compare active JTL vs myth mode (passive wire).

Active JTL: every stage switches → new Φ₀ token → pulse reaches the end. Myth mode: without regeneration the token fades — SFQ interconnect is not free metal. For whole missing epochs, use DFF pads (pipeline lab), not only JTL trim.