Supercritically superlubric

Characteristic thermal energy kT exceeding the remnant energy waviness of the energy potential along the sliding direction(s).

Not truly zero friction. => Actually zero static(!) friction after all.

The reader might have encountered statements like:
"Superlubricity is not like superconductivity as there is no sudden qualitatye jump to unmeasurably small friction"

That is actually only true …

• speed dependent friction
• for the broad concept of suprlubricity.
• for pretty much all what is today (2026) expermentally acessible.

We have an exception for static friction in as of yet (2026)
likely experimentaly still inacessible systems.

The qualitative change

The "supercritical" in the title refers to characteristic thermal energy kT exceeding lsiding ebnergy potential waviness.

There is a qualitative change happening
when the thermal enegy kT suddenly exceeds the remnant energy waviness of the surface contact sliding potential.
Causing static friction to go to literally zero or rather making it stop to make sense.
Granted while a qualitatibve change not a very sharp and sudden change.

Even if there is no force present at all the sliding interface diffuses around.
So every epsilon of force (no matter how small) will eventualy lead to a motion in this driving direction.
The hallmark of zero static friction.

Possible criticism of the concept

One could argue that diffusion happens at low temperatures and high energy barriers too just exponentially slower.
So in that sense static friction is always zero. That's a bit absurd though.

In this case there is a clead distinction between
– Diffusiion direction probabilty being skewed by force and
– static friction being overcome startung a maningfully fast motion.

Latter case one could look if there is an acceleration happening
but this goes quickly into dynamic fricion instead.

There sould be a point where these two start blurring together.
This might not exactly coincide with the criticality criterion here, but is should roughly.

Enginering / encountering supercritical superlubricity

Supercriticality of superlubricity (as defined here) can be ebbginnered or happen by …

• reduction of waviness from more incommensural interface (rotations, other sirface pairings)
• reduction of waviness from cange of uinterface distance and/or pressure
• raising of temperatue so log the matrials and surfacs still tolerate it

Challenge of achieving the effect

The effect described here mayb be somewhat challenging to realize.
Needed is a very small surface contact area
yet still big enough for superbubricity
and that at sufficiently high temperatues.

Overpowered remnant static friction for the possibly subcritical superlubrication cases

A usually more interesting and practically relevant question:
For subcritical superlubric cases or even non subperllubric cases:
Do vdW suck-in forces overpower the remnant sliding energy potential waviness or not.
In other words: Is the vdW slide-on threshold exceded or not?

Related

• Superlubricity
• Design of crystolecules