Physical world and mathematics

Qiang Xu

Qiang Xu (徐强) is a chemist working on metal–organic framework catalysts for energy, Chair Professor at SUSTech in Shenzhen since 2020 after a career at Japan's AIST.

Qiangtang terrane

The Qiangtang terrane is a continental block in northern central Tibet, bounded by the Jinsha and Bangong-Nujiang suture zones, that drifted north from Gondwana as part of the Cimmerian continent.

Qichun Zhang

Qichun Zhang (张其春, born 1970) is a materials chemist and full professor at City University of Hong Kong, known for covalent organic frameworks used as battery electrode materials.

Qihua Xiong

Qihua Xiong (熊启华) is a Chinese physicist working on optical spectroscopy of quantum matter, Professor at Tsinghua University since 2021 and known for the first laser cooling of a semiconductor.

Qimiao Si is a theoretical condensed matter physicist and Wiess Professor at Rice University, known for local quantum criticality in heavy fermion metals, iron-based superconductors, and the Weyl-Kondo semimetal.

Qiming Zhang

Qiming Zhang is an electrical engineer and materials scientist at Penn State, known for inventing relaxor ferroelectric polymers and discovering the giant electrocaloric effect in polymers.

Qingying Jia

Qingying Jia is an electrochemist known for work on iron–nitrogen–carbon fuel cell catalysts and hydrogen electrocatalysis, and a recipient of the 2023 ACS ENFL Emerging Researcher Award.

Qiong Ma

Qiong Ma (马琼) is a Chinese-born condensed matter physicist and Associate Professor of Physics at Boston College, known for the 2019 nonlinear Hall effect paper in Nature.

QIP (complexity)

QIP, or Quantum Interactive Polynomial time, is the complexity class of decision problems with quantum interactive proof systems; Jain, Ji, Upadhyay, and Watrous proved it equals PSPACE in 2009.

Qiskit

Qiskit is an open-source, Python-based SDK developed by IBM for writing and running programs on quantum computers, offering circuit construction, a transpiler, and access to IBM Quantum processors.

Qiu Cheng Wei

Qiu Cheng Wei, published as Cheng-Wei Qiu, is a Singapore-based optical scientist and Provost's Chair Professor at the National University of Singapore, known for optical tractor beams and the 2023 President's Science Award.

QM/MM

QM/MM, short for quantum mechanics/molecular mechanics, is a hybrid computational method combining quantum treatment of a chemically active region with cheaper classical molecular mechanics around it.

Sep 29, 2026

QM/MM simulation

QM/MM simulation is a computational chemistry method treating a small reactive region quantum mechanically within a molecular mechanics environment, recognized by the 2013 Nobel Prize in Chemistry.

Oct 22, 2026

QM7-X

QM7-X is a dataset of quantum-mechanically computed properties for about 4.2 million equilibrium and non-equilibrium structures of small organic molecules with up to seven heavy atoms, published in 2021 for training machine-learning models.

QMA

QMA, or Quantum Merlin Arthur, is a quantum complexity class often described as quantum NP, introduced by Alexei Kitaev in 1999 with the local Hamiltonian problem as its canonical complete problem.

Oct 22, 2026

QMOF Database

The QMOF Database is a public dataset of quantum-chemical properties for more than 20,000 metal–organic frameworks, computed with density functional theory and first released in 2021 by Andrew S. Rosen and colleagues at Northwestern University.

QR algorithm

The QR algorithm, or QR method, is an iterative numerical method for computing the eigenvalues of a square matrix, devised by J. G. F. Francis in 1961.

QR decomposition

The QR decomposition, also called QR factorization, expresses a matrix A as A = QR with Q orthogonal and R upper triangular, and underlies least-squares fitting and eigenvalue computation.

qRAM and state-preparation oracles for quantum linear algebra

qRAM and state-preparation oracles for quantum linear algebra are the input models for loading classical data into quantum states, whose cost decides whether claimed speedups survive end to end.

QSO B0420-0127

QSO B0420-0127, also known as PKS 0420-014 and 4FGL J0423.3-0120, is a blazar in Orion at redshift 0.916, a flat-spectrum radio quasar whose superluminal jet has been monitored across the spectrum since 1969.

QSO B1730-130

QSO B1730-130, also known as NRAO 530 or PKS 1730-130, is a blazar at redshift 0.90 and the most distant object imaged by the Event Horizon Telescope.

QSO J0529−4351

QSO J0529−4351 (SMSS J052915.80−435152.0) is a quasar in the constellation Pictor identified in 2024 as the most luminous quasar known, powered by a 17-billion-solar-mass black hole.

QSO J0738+1742

QSO J0738+1742, also known as PKS 0735+178, is a BL Lacertae object, a blazar whose relativistic jet points nearly at Earth; in 2021 it became a candidate source of an IceCube neutrino.

QSO J1512-0906

QSO J1512-0906, better known in the literature as PKS 1510-089, is a flat-spectrum radio quasar at redshift 0.361 with a jet pointed almost directly at Earth.

QUADAS-2

QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2) is a tool published in 2011 to assess risk of bias and applicability of diagnostic accuracy studies in systematic reviews.

Quadrantids

The Quadrantids are an annual meteor shower peaking early January, one of the strongest of the year, with an asteroid parent body and a name from a constellation that no longer exists.

Quadratic assignment problem

The quadratic assignment problem (QAP) is a strongly NP-hard combinatorial optimization problem, introduced by Koopmans and Beckmann in 1957, of assigning facilities to locations to minimize total cost.

Quadratic equation

A quadratic equation, also called a second degree equation, is a polynomial equation of degree two, written ax² + bx + c = 0 and solved by the quadratic formula.

Quadratic field

A quadratic field is a number field of degree 2 over the rationals, of the form Q(√d) for a unique squarefree integer d; real when d > 0, imaginary when d < 0.