Our Work

Teleportation-based Gottesman--Kitaev--Preskill (GKP) error correction typically assumes a decoherence-free GKP ancilla Bell pair, an idealization that is difficult to reconcile with the ubiquitous en…

Teleportation-based Gottesman--Kitaev--Preskill (GKP) error correction typically assumes a decoherence-free GKP ancilla Bell pair, an idealization that is difficult to reconcile with the ubiquitous environmental decoherence in bosonic systems. Here, we analyze the performance of the GKP protocol subject to pure-dephasing processes, ubiquitous in realistic situations. We show that, under this class of interactions, teleportation, instead of projecting the input onto the GKP subspace, transforms GKP error correction into a correlated Pauli--Gaussian noise process that can accumulate over successive correction rounds. Thus, unlike in previously studied noisy GKP scenarios, the code no longer self-corrects. Moreover, repeated noisy GKP teleportation drives the encoded modes out of the logical subspace, progressively degrading the encoded codewords. We show that the resulting leakage rapidly saturates with the number of correction rounds. Finally, we investigate the implications of our results for motional-oscillator-based GKP error-correction platforms.

Compact pre-adjudication checkpoint for Living Evidence Map Workflow 01.It stores only the incremental source manifestations, pair decisions, LLM adjudications and locked human-review queue required t…

Compact pre-adjudication checkpoint for Living Evidence Map Workflow 01.It stores only the incremental source manifestations, pair decisions, LLM adjudications and locked human-review queue required to resume from Workflow 01 Zenodo record 23096518. It does not duplicate the full corpus.Pending human-review cases: 55.

In the folded-histories reformulation of the path integral, the two-state-vector formalism acquires a coupling constant: forward- and backward-evolving states exchange amplitude at rate $\Delta$. This…

In the folded-histories reformulation of the path integral, the two-state-vector formalism acquires a coupling constant: forward- and backward-evolving states exchange amplitude at rate $\Delta$. This paper answers the question that result raises ---how would one measure $\Delta$? and four results are new. First, a parity selection rule: the signed metric intertwines the generators exactly, $GH(\Delta)G=H(-\Delta)$, so with absorber-defined boundary data every sense-blind observable is an even function of $\Delta$; all intensity-based signatures begin at second order, and first-order access requires sense-superposed boundary data or sense-odd probes.  Second, the information is nonetheless there: the quantum Fisher information about $\Delta$ is finite at $\Delta=0$ even for physical preparation -it resides in the amplitude, and we exhibit the hierarchy exactly: at $\Delta=0.02$ (in units of the turn rate) the intensity pointer protocol captures $0.155\%$ of the QFI, a bare sense-odd projective measurement $36\%$, and the locally optimal basis all of it.  Third, an exact weak-value-amplification verdict for this system: because the measured observable has eigenvalues $\pm1$ the pointer protocol is closed form, and sweeping the post-selection overlap at linearity-saturating coupling shows no fundamental gain -total Fisher information per trial dips and plateaus- but seventy-fold concentration of information per detected event, a node at which the click rate is momentarily blind to $\Delta$, and a revival beyond it where click statistics carry a comparable share. Fourth, a design equation: the population-inverted absorber, the one proposed measurement requiring no new instrument, is Fourier-limited with detectability threshold $\Delta_{\min}T_w=2\hbar|\sin(ET_w/\hbar)|\le2\hbar$, independent of the particle energy on the envelope -integration time alone sets the reachable coupling.

This is a release to archive data with Zenodo.

README updated from v2.0

Discover how reKraftt repurposes construction and demolition waste into unfired bricks, paver blocks, etc. driving sustainable architecture.  

README updated from v1.0

Sorkin defined a quantum measure as a set function on histories that is nonnegative, permits two-way interference, and satisfies the sum rule that forbids three-way interference. We show that the two-…

Sorkin defined a quantum measure as a set function on histories that is nonnegative, permits two-way interference, and satisfies the sum rule that forbids three-way interference. We show that the two-boundary measure of the folded-histories theory (the theory obtained from Feynman's sum by allowing a history to turn in time with an amplitude per unit time Delta) is a quantum measure in this sense for every value of Delta: it arises from a Hermitian, biadditive, strongly positive decoherence functional, and its measure of the whole history space exceeds unity by exactly the squared norm of the backward-in-time strand, which the second-quantized theory identifies as the flux of created pairs. The measure is Sorkin's double sum over histories with one added condition: histories interfere only if they end on the same strand, and only the forward strand is counted. The signed crossing count, which the fold conserves, also satisfies the sum rule but is not positive; Sorkin's positivity axiom excludes it; among the positive pairings that remain, the absorber selects the one restricted to the strand it reads. In unitary quantum measure theory a serial event, one defined by a sequence of projectors, cannot exceed unity; in the folded theory the whole history space, a serial event specified by identity projectors, does whenever the backward strand is populated. A serial event whose measure exceeds unity is therefore the signature of evolution that is not unitary; for the free electron, the only such mechanism in the theory is the turn. The fold introduces two-way interference between strand-resolved classes, while preserving the absence of three-way interference at every real Delta. We prove the measure identities, outline an optical test, and report a finite-system numerical audit.

The outgassing solver no longer accepts a root whose negative partial pressure still carries mass. Such a root reported CH4 and H2S formed from a negative pH2O; for a low-H, C-rich inventory about one…

The outgassing solver no longer accepts a root whose negative partial pressure still carries mass. Such a root reported CH4 and H2S formed from a negative pH2O; for a low-H, C-rich inventory about one cold start in four or five landed on it. A root with a negative primary is now judged and reported in its clipped form, and roots with all pressures positive are unchanged (#36). Very small hydrogen budgets far below the solver tolerance can now take most of the allowed attempts; the mass balance page gives the measured cost. Also: test-count badges from CI, the shared PROTEUS docs theme, and a test that fails when a pre-commit exclusion stops matching (#26, #27).