Everything from pairs: the quantum Ising chain in the Dirac basisAlles aus Paaren: die Quanten-Ising-Kette in der Dirac-Basis
Appendix C of our paper: in the Dirac basis, every amplitude of the Ising ground state is a Pfaffian of one pair matrix, which obeys a single matrix Riccati equation.
From bits to trits: spin-1 operators as base-3 numbersVon Bits zu Trits: Spin-1 im Dreiersystem
A spin 1 has three positions. Read them as the digits 0, 1, 2, and spin-1 operators become jumps between integers written in base 3.
The Haldane chain: a gap that should not be thereDie Haldane-Kette: eine unerwartete Energielücke
Integer spins keep an energy gap, hide a perfect up–down order and carry half spins at their ends. We compute it all exactly with our base-3 representation.
One machine, all the energies: perturbation theory with matricesEine Maschine für alle Energien
A compact matrix recursion gives every eigenvalue and eigenstate at once, to any order. We run it, and show exactly when and why it breaks.
Can a quantum system remember its past? Many-body localisationKann sich ein Quantensystem erinnern?
Most systems forget where they started. With strong disorder, interacting quantum spins can refuse to. Three fingerprints, computed exactly.
How to build a Word ⇄ LaTeX converter: the design of DeepQ ManuscriptWie man einen Word-⇄-LaTeX-Konverter baut
The architecture and the algorithms behind DeepQ Manuscript, explained step by step with figures and pseudocode. Free to read, reuse and build upon.
Quantum spins are just binary numbersQuantenspins sind Binärzahlen
Read a chain of spins as a binary number, and spin operators become simple jumps between integers: the idea behind our Dirac representation.
Perturbation theory explained like you’re 10Störungstheorie, kindgerecht erklärt
Tiny magnets on a bumpy road: how physicists estimate energies when the exact problem is too hard, step by step and with real numbers.