English
Related papers

Related papers: Group Theoretical Classification of SIC-POVMs

200 papers

We propose an experiment that realizes a symmetric informationally complete (SIC) probability-operator measurement (POM) in the four-dimensional Hilbert space of a qubit pair. The qubit pair is carried by a single photon as a polarization…

Quantum Physics · Physics 2015-06-04 Amir Kalev , Jiangwei Shang , Berthold-Georg Englert

In this paper, we prove several stability theorems for multiplicities of naturally defined representations of symmetric groups. The first such theorem states that if we consider the diagonal action of the symmetric group $S_{m+r}$ on $k$…

Representation Theory · Mathematics 2024-06-19 Marino Romero , Nolan Wallach

Since Renes et al. [J. Math. Phys. 45, 2171 (2004)], there has been much effort in the quantum information community to prove (or disprove) the existence of symmetric informationally complete (SIC) sets of quantum states in arbitrary finite…

Quantum Physics · Physics 2010-06-29 D. M. Appleby , Hoan Bui Dang , Christopher A. Fuchs

Zauner's conjecture concerns the existence of $d^2$ equiangular lines in $\mathbb{C}^d$; such a system of lines is known as a SIC. In this paper, we construct infinitely many new SICs over finite fields. While all previously known SICs…

Metric Geometry · Mathematics 2025-06-27 Joseph W. Iverson , Dustin G. Mixon

Let $G$ be a finite group, and $S$ be a subset of $G\setminus\{1\}$ such that $S=S^{-1}$. Suppose that $Cay(G,S)$ is the Cayley graph on $G$ with respect to the set $S$ which is the graph whose vertex set is $G$ and two vertices $a,b\in G$…

Combinatorics · Mathematics 2015-05-05 Alireza Abdollahi , Shahrooz Janbaz , Mojtaba Jazaeri

We continue the study of non-commutative operator graphs generated by resolutions of identity covariant with respect to unitary actions of the circle group and the Heisenber-Weyl group as well. It is shown that the graphs generated by the…

Quantum Physics · Physics 2019-08-19 G. G. Amosov , A. S. Mokeev

Covariant or invariant functions under a compact linear group can be expressed in terms of functions defined in the orbit space of the group. The semialgebraic relations defining the orbit spaces of all finite coregular real linear groups…

High Energy Physics - Theory · Physics 2008-11-26 G. Sartori , G. Valente

The aim of this paper is to establish a pseudo-differential Weyl calculus on graded nilpotent Lie groups $G$ which extends the celebrated Weyl calculus on $\mathbb{R}^n$. To reach this goal, we develop a symbolic calculus for a very general…

Analysis of PDEs · Mathematics 2026-03-13 Serena Federico , David Rottensteiner , Michael Ruzhansky

The canonical commutation relation, $[Q,P] = i\hbar$, stands at the foundation of quantum theory and the original Hilbert space. The interpretation of $P$ & $Q$ as observables has always relied on the analogies that exist between the…

Quantum Physics · Physics 2023-08-30 Christopher S. Jackson , Carlton M. Caves

Mutually Unbiased Bases (MUBs) constitute a fundamental geometric structure in quantum theory, known for providing an optimal measurement scheme for quantum state tomography. In prime and prime-power dimensions, analytical constructions of…

Quantum Physics · Physics 2026-04-07 Buğra Gültekin , Solomon B. Samuel , Zafer Gedik

We introduce shortcut graphs and groups. Shortcut graphs are graphs in which cycles cannot embed without metric distortion. Shortcut groups are groups which act properly and cocompactly on shortcut graphs. These notions unify a surprisingly…

Group Theory · Mathematics 2021-09-10 Nima Hoda

It is a well-known fact that the optimal POVM for quantum state tomography is the symmetric, informationally complete, positive operator valued measure (SIC-POVM). We investigate the same problem only in the case when there are some a…

Quantum Physics · Physics 2015-11-23 Dénes Petz , László Ruppert

Recently, several intriguing conjectures have been proposed connecting symmetric informationally complete quantum measurements (SIC POVMs, or SICs) and algebraic number theory. These conjectures relate the SICs and their minimal defining…

Quantum Physics · Physics 2018-03-28 Marcus Appleby , Tuan-Yow Chien , Steven Flammia , Shayne Waldron

The geometric crystal operators and geometric $R$-matrices (or geometric Weyl group actions) give commuting actions on the field of rational functions in $mn$ variables. We study the invariants of various combinations of these actions,…

Quantum Algebra · Mathematics 2022-05-26 Benjamin Brubaker , Gabriel Frieden , Pavlo Pylyavskyy , Travis Scrimshaw

In this paper, we investigate nilpotent and unimodular solvable Lie groups that admit quasi-Einstein metrics $(M,g,X)$ with $X$ a left-invariant vector field, which we call totally left-invariant quasi-Einstein metrics. We give a complete…

Differential Geometry · Mathematics 2025-09-30 Nazia Valiyakath

We show that mod $2$ cohomological invariants of the moduli stack $\mathscr{M}_{3,n}$ of smooth pointed curves of genus three contain a free module with generators in degree $0$, $2$, $3$, $4$ and $6$, formed by the invariants of the…

Algebraic Geometry · Mathematics 2025-09-12 Andrea Di Lorenzo

We investigate the group $\mathcal{H}_\mathbb{C}$ of complexified Heisenberg matrices with entries from an infinite-dimensional complex Hilbert space $H$. Irreducible representations of the Weyl--Schr{\"o}dinger type on the space $L^2_\chi$…

Functional Analysis · Mathematics 2020-04-28 Oleh Lopushansky

Generalized quantum measurements (also known as POVMs) are of great importance in quantum information and quantum foundations, but often difficult to perform. We present an experimental approach which can in principle be used to perform…

Using an interplay between geometric methods in group theory and soft von Neuman algebraic techniques we prove that for any icc, acylindrically hyperbolic group $\Gamma$ its von Neumann algebra $L(\Gamma)$ satisfies the so-called ISR…

Operator Algebras · Mathematics 2023-02-17 Ionut Chifan , Sayan Das , Bin Sun

The groups mentioned in the title are certain matrix groups of infinite size over a finite field $\mathbb F_q$. They are built from finite classical groups and at the same time they are similar to reductive $p$-adic Lie groups. In the…

Representation Theory · Mathematics 2022-06-15 Cesar Cuenca , Grigori Olshanski