Reference: https://doi.org/10.5281/zenodo.17594186
What if the way light twists in magnetized crystals wasn’t just a messy material effect, but the shadow of a single, universal rule?
In ordinary magneto-optics, the Faraday rotation angle θ — how much the polarization of light rotates in a magnetic crystal — is treated as a material-dependent constant. Each crystal gets its own “Verdet constant”, tuned from data, with no deeper story.
Quantum Traction Theory (QTT) says something much stronger:
The rotation angle is a geometric holonomy, set by how much “capacity” the light’s magnetic field dumps into the spins, in units of a single universal angle per capacity quantum.
The recent “integer capacity holonomy” Faraday test takes this seriously and asks: if we trust QTT’s core machinery, can one formula with one universal scale explain Faraday rotation in several different terbium-based crystals?
The short answer: yes, within about 5–10% across multiple materials, with no per-crystal tuning.
Step 1 – What is actually being tested?
Let’s strip the jargon away.
- Light carries an oscillating magnetic field. QTT treats this as carrying a certain amount of optical capacity – call it Hcap.
- A magnetized crystal has many spins (like tiny bar magnets). Lining them up takes spin capacity – call that NSQ(S).
- QTT says there is a universal “clock factor” Iclk = cos(π/8) that turns capacity into a rotation angle.
The bold claim is:
Faraday rotation angle = (universal angle per capacity quantum) × (optical capacity) / (spin capacity).
In symbols: once you fix the overall scale C* once (on one crystal), the same formula with the same Iclk should work for all similar materials without further adjustment.
The test uses real data from Tb-based garnets (TGG, TSAG, TAG) and Tb-glass, and checks whether this single QTT formula can hit all their Faraday plateau values to within experimental uncertainty.
Step 2 – The physical picture, in plain language
Two players: the light and the spins
Imagine you send a linearly polarized light pulse through a magnetized crystal:
- The light’s magnetic field wiggles along the path. QTT says that over the duration of the pulse and the cross-section of the beam, this wiggling stores a certain amount of capacity in the optical field (Hcap).
- Inside the crystal, many Tb3+ ions carry spins. Aligning them in the external field builds up a spin capacity (NSQ(S)), proportional to spin density, effective moment, and saturation field.
A single universal angle per “capacity quantum”
QTT then says:
Every time you transfer one “quantum” of capacity from the light to the spins, the polarization dial rotates by a fixed angle:
2π × Iclk, where Iclk = cos(π/8).
So the total rotation angle is just:
- how many capacity quanta the light carries (Hcap),
- divided by how many capacity quanta the spins can absorb (NSQ(S)),
- times the universal angle 2π Iclk.
One calibration, then no more knobs
In practice, there are geometric details (beam area, interaction time, etc.), so all those are absorbed into a single global constant C*. The procedure is:
- Use TGG data to fix C* once – that’s your calibration.
- Keep C* and Iclk fixed.
- For TSAG, TAG, and Tb-glass, compute their optical capacity Hcap and spin capacity NSQ(S), then predict their Faraday rotation using the same formula.
The key result: those predictions match the measured Faraday plateaus within about 5–10%, without any extra fudge factors per material.
Step 3 – What does this tell us about QTT’s axioms?
Without going into the full formal list of axioms, here’s what is really being exercised:
1. Two clocks and background time (Axiom A1)
QTT distinguishes between:
- a hidden background clock (T), and
- our usual dial time (what lab instruments read).
The optical capacity Hcap is explicitly defined as an integral over the background time T, not just over the lab dial:
Light’s magnetic field feeds a ledger measured in units of a universal capacity quantum.
The test shows that, once you use this background-time based definition, you get a stable Hcap that makes sense across different crystals and predicts their rotation angles correctly.
2. A single U(1) coupling between light and spin (Axiom A4)
QTT says there is one and only one internal “dial” coupling between the electromagnetic field and spin, encoded in the factor 2π Iclk.
The test assumes that the same factor applies in all three garnets and the glass. The successful cross-material prediction is strong evidence that you don’t need a different “magneto-optic coupling constant” for each material at the capacity level – the main differences are captured by their capacities (Hcap, NSQ(S)), not by a new angle.
3. Capacity / endurance and finite holonomy (Axiom A6)
A6 is the statement that any finite response of a system is a ratio:
- integrated capacity divided by
- a universal “endurance quantum” E*,
- and that finite holonomies (like rotation angles) come in units of 2π Iclk per capacity quantum.
The test uses this literally: both Hcap and NSQ(S) are defined as capacities normalized by E*, then the angle is given by their ratio. The fact you can use the same underlying endurance scale across different materials is a concrete confirmation of this idea.
4. Bundled existence / “integer” capacities (Axiom A7)
A7 says capacities come in bundles (quanta). In the report, when you measure capacities relative to TGG’s plateau, the normalized Hcap and NSQ(S) for TSAG and TAG are both very close to 1 in those units. That’s compatible with an “integer” picture – you don’t see some crystal demanding 5 or 10 times the capacity for no reason.
The data are not yet precise enough to shout “exactly integer!” – but they are fully consistent with the idea that similar systems sit near small integer bundles of capacity, rather than wandering off arbitrarily.
Step 4 – The core QTT equation that went on trial
Now the promised equations, in WordPress LaTeX shortcode format.
(a) Capacity holonomy law for Faraday rotation
The central QTT prediction tested is:
where:
is the universal clock factor, fixed once and for all.
is the optical capacity (from the light’s magnetic field).
is the spin capacity (from aligning the spins in the material).
(b) Optical capacity from the light field
The capacity carried by the optical magnetic field is
where:
: magnetic component of the light field,
: vacuum permeability,
: universal endurance quantum (capacity per tick of the background clock
),
- integration is over the beam cross-section and pulse duration in background time
.
In practice, all geometric and temporal factors are absorbed into a single global constant , calibrated once on TGG.
(c) Spin capacity from material properties
The spin capacity is built from the spin energy density, which in the simplest plateau model scales as
where
: density of magnetic ions (e.g. Tb3+),
: effective magnetic moment per ion,
: saturation field for spin alignment.
Again, the overall proportionality is included in the global scale determined from TGG.
(d) Plateau-limit prediction used in practice
In the uniform-beam, plateau regime used in the test, the QTT prediction reduces to a very simple scaling law:
where
: optical intensity,
: group velocity in the medium.
All Tb-garnets and Tb-glass are fitted with a single and the same
. The ratio
for all tested materials – that is the concrete success of the test.
Step 5 – Why this matters beyond magneto-optics
This is not “just another fit” to Verdet constants. It is a check of QTT’s core language in a real solid-state system:
- Responses written as ratios of capacities,
- angles quantized in units of 2π Iclk,
- one global endurance scale
instead of separate scales for each material,
- and capacities that look bundled, not arbitrary.
Those are the same ingredients QTT uses when it goes after much more “fundamental” targets, like lepton masses and neutrino splittings. Seeing them work, quantitatively, in Faraday rotation with no per-material knobs is one of the cleanest validations so far that the QTT machinery is not just formalism – it does real numerical work in real crystals.