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Usually models for quantum computations deal with unitary gates on pure states. In this paper we generalize the usual model. We consider a model of quantum computations in which the state is an operator of density matrix and the gates are…

Quantum Physics · Physics 2007-05-23 Vasily E. Tarasov

We develop a systematic approach to determine and measure numerically the geometry of generic quantum or "fuzzy" geometries realized by a set of finite-dimensional hermitian matrices. The method is designed to recover the semi-classical…

High Energy Physics - Theory · Physics 2016-06-22 Lukas Schneiderbauer , Harold C. Steinacker

We study the noncommutative geometrical structures of quantum entangled states. We show that the space of a pure entangled state is a noncommutative space. In particular we show that by rewritten the conifold or the Segre variety we can get…

Quantum Physics · Physics 2015-05-19 Hoshang Heydari

We introduce a class of generalized geometric measures of entanglement. For pure quantum states of $N$ elementary subsystems, they are defined as the distances from the sets of $K$-separable states ($K=2,...,N$). The entire set of…

Quantum Physics · Physics 2009-07-02 M. Blasone , F. Dell'Anno , S. De Siena , F. Illuminati

In this paper, we address a foundational challenge in quantum field theory on curved spacetime by developing a consistent framework within loop quantum gravity. We introduce a methodology for defining meaningful superpositions of quantum…

General Relativity and Quantum Cosmology · Physics 2026-02-17 Gaoping Long , Cong Zhang

Quantifying entanglement is an important issue in quantum information theory. Here we consider the entanglement measures through the trace norm in terms of two methods, the modified measure and the extended measure for bipartite states. We…

Quantum Physics · Physics 2023-02-09 Xian Shi , Lin Chen , Yixuan Liang

The geometrical description of Quantum Mechanics is reviewed and proposed as an alternative picture to the standard ones. The basic notions of observables, states, evolution and composition of systems are analised from this perspective, the…

Mathematical Physics · Physics 2019-03-26 Florio M. Ciaglia , Alberto Ibort , Giuseppe Marmo

In the framework of the method of constraint system quantization, a quantum gravitational system (QGS) with the maximally symmetric geometry is studied. The state vector of the QGS satisfies the set of wave equations which describes the…

General Relativity and Quantum Cosmology · Physics 2019-11-05 V. E. Kuzmichev , V. V. Kuzmichev

Computing entanglement of an arbitrary bipartite or multipartite mixed state is in general not an easy task as it usually involves complex optimization. Here we show that exploiting symmetries of certain mixed states, we can compute a…

Quantum Physics · Physics 2016-08-31 Tamoghna Das , Sudipto Singha Roy , Shrobona Bagchi , Avijit Misra , Aditi Sen De , Ujjwal Sen

The geometric measure of entanglement for a symmetric pure state with nonnegative amplitudes has attracted much attention. On the other hand, the spectral theory of nonnegative tensors (hypermatrices) has been developed rapidly. In this…

Quantum Physics · Physics 2015-03-13 Shenglong Hu , Liqun Qi , Guofeng Zhang

We show that it is possible to represent various descriptions of Quantum Mechanics in geometrical terms. In particular we start with the space of observables and use the momentum map associated with the unitary group to provide an unified…

Mathematical Physics · Physics 2008-11-26 J. F. Carinena , J. Clemente-Gallardo , G. Marmo

We study the geometric measure of entanglement (GM) of pure symmetric states related to rank-one positive-operator-valued measures (POVMs) and establish a general connection with quantum state estimation theory, especially the maximum…

Quantum Physics · Physics 2011-01-17 Lin Chen , Huangjun Zhu , Tzu-Chieh Wei

A large-scalable quantum computer model, whose qubits are represented by the subspace subtended by the ground state and the single exciton state on semiconductor quantum dots, is proposed. A universal set of quantum gates in this system may…

Quantum Physics · Physics 2009-11-10 Kaiyu Yang , Shi-Liang Zhu , Z. D. Wang

The computational complexity of a quantum state quantifies how hard it is to make. `Complexity geometry', first proposed by Nielsen, is an approach to defining computational complexity using the tools of differential geometry. Here we…

High Energy Physics - Theory · Physics 2021-04-01 Adam R. Brown , Leonard Susskind

Everett's concept of relative state is used to introduce a geometric phase that depends nontrivially on entanglement in a pure quantum state. We show that this phase can be measured in multiparticle interferometry. A correlation-dependent…

Quantum Physics · Physics 2015-05-13 Erik Sjöqvist

In this paper we review a proposed geometrical formulation of quantum mechanics. We argue that this geometrization makes available mathematical methods from classical mechanics to the quantum frame work. We apply this formulation to the…

Mathematical Physics · Physics 2014-11-21 G. Marmo , G. F. Volkert

We consider the problem of designing an optimal quantum detector with a fixed rate of inconclusive results that maximizes the probability of correct detection, when distinguishing between a collection of mixed quantum states. We develop a…

Quantum Physics · Physics 2009-11-07 Yonina C. Eldar

Practical implementations of quantum computing are always done in the presence of decoherence. Geometric phase is useful in the context of quantum computing as a tool to achieve fault tolerance. Recent experimental progresses on coherent…

Quantum Physics · Physics 2010-01-03 Sun Yin , D. M. Tong

We define a time-dependent extension of the quantum geometric tensor to describe the geometry of the time-parameter space for a quantum state, by considering small variations in both time and wave function parameters. Compared to the…

Quantum Physics · Physics 2025-02-05 Bogar Díaz , Diego Gonzalez , Marcos J. Hernández , J. David Vergara

Quantum geometric tensor (QGT), which is usually obtained by evaluating the quantum distance between Bloch states parametrized by momentum, plays a key role in exploring the exotic responses of quantum materials. Herein, we revisit the…

Mesoscale and Nanoscale Physics · Physics 2025-04-29 Longjun Xiang , Jinxiong Jia , Fuming Xu , Zhenhua Qiao , Jian Wang