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Related papers: QMA/qpoly Is Contained In PSPACE/poly: De-Merliniz…

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This paper studies whether quantum proofs are more powerful than classical proofs, or in complexity terms, whether QMA=QCMA. We prove three results about this question. First, we give a "quantum oracle separation" between QMA and QCMA. More…

Quantum Physics · Physics 2020-09-30 Scott Aaronson , Greg Kuperberg

In this paper we consider a quantum computational variant of nondeterminism based on the notion of a quantum proof, which is a quantum state that plays a role similar to a certificate in an NP-type proof. Specifically, we consider quantum…

Computational Complexity · Computer Science 2007-05-23 John Watrous

We prove that QIP(2), the class of problems having two-message quantum interactive proof systems, is a subset of PSPACE. This relationship is obtained by means of an efficient parallel algorithm, based on the multiplicative weights update…

Computational Complexity · Computer Science 2009-05-11 Rahul Jain , Sarvagya Upadhyay , John Watrous

Complexity theory traditionally studies the hardness of solving classical computational problems. In the quantum setting, it is also natural to consider a different notion of complexity, namely the complexity of physically preparing a…

Quantum Physics · Physics 2023-04-11 Tony Metger , Henry Yuen

Polynomial quantified entailments with existentially and universally quantified variables arise in many problems of verification and program analysis. We present PolyQEnt which is a tool for solving polynomial quantified entailments in…

This article presents a technique for proving problems hard for classes of the polynomial hierarchy or for PSPACE. The rationale of this technique is that some problem restrictions are able to simulate existential or universal quantifiers.…

Artificial Intelligence · Computer Science 2007-08-31 Paolo Liberatore

We consider a hypothetical apparatus that implements measurements for arbitrary 4-local quantum observables A on n qubits. The apparatus implements the ``measurement algorithm'' after receiving a classical description of A. We show that a…

Quantum Physics · Physics 2007-05-23 Pawel Wocjan , Dominik Janzing , Thomas Decker , Thomas Beth

The concept of entanglement and separability of quantum states is relevant for several fields in physics. Still, there is a lack of effective operational methods to characterise these features. We propose a method to certify quantum…

Quantum Physics · Physics 2024-03-06 Ties-A. Ohst , Xiao-Dong Yu , Otfried Gühne , H. Chau Nguyen

It is a long-standing open question to construct a classical oracle relative to which BQP/qpoly $\neq$ BQP/poly or QMA $\neq$ QCMA. In this paper, we construct classically-accessible classical oracles relative to which BQP/qpoly $\neq$…

Quantum Physics · Physics 2024-01-19 Xingjian Li , Qipeng Liu , Angelos Pelecanos , Takashi Yamakawa

In recent years, the quantum oracle model introduced by Aaronson and Kuperberg (2007) has found a lot of use in showing oracle separations between complexity classes and cryptographic primitives. It is generally assumed that proof…

Quantum Physics · Physics 2026-02-04 Avantika Agarwal , Srijita Kundu

In this paper we consider the relationship between monomial-size and bit-complexity in Sums-of-Squares (SOS) in Polynomial Calculus Resolution over rationals (PCR/$\mathbb{Q}$). We show that there is a set of polynomial constraints $Q_n$…

Computational Complexity · Computer Science 2021-05-18 Tuomas Hakoniemi

Quantum signal processing (QSP) represents a real scalar polynomial of degree $d$ using a product of unitary matrices of size $2\times 2$, parameterized by $(d+1)$ real numbers called the phase factors. This innovative representation of…

Quantum Physics · Physics 2024-12-11 Yulong Dong , Lin Lin , Hongkang Ni , Jiasu Wang

We prove that the vast majority of symmetric states of qubits can be decomposed in a unique way into a superposition of spin 1/2 coherent states. For the case of two qubits, the proposed decomposition reproduces the Schmidt decomposition…

Quantum Physics · Physics 2015-06-25 A. Mandilara , T. Coudreau , A. Keller , P. Milman

We describe the encoding of multiple qubits per atom in trapped atom quantum processors and methods for performing both intra- and inter-atomic gates on participant qubits without disturbing the spectator qubits stored in the same atoms. We…

Quantum Physics · Physics 2022-10-28 Wesley C. Campbell , Eric R. Hudson

We give algorithms for the optimization problem: $\max_\rho \ip{Q}{\rho}$, where $Q$ is a Hermitian matrix, and the variable $\rho$ is a bipartite {\em separable} quantum state. This problem lies at the heart of several problems in quantum…

Quantum Physics · Physics 2011-12-06 Yaoyun Shi , Xiaodi Wu

We give an alternative proof of PreciseQMA = PSPACE, first proved by Fefferman and Lin (Innov. Theor. Comp. Sci. 2018), where PreciseQMA is the class Quantum Merlin-Arthur with inverse exponential completeness-soundness gap. We adapt the…

Quantum Physics · Physics 2022-06-22 Yulong Li

Any technology for quantum information processing (QIP) must embody within it quantum bits (qubits) and maintain control of their key quantum properties of superposition and entanglement. Typical QIP schemes envisage an array of physical…

Quantum Physics · Physics 2009-11-13 Joseph Fitzsimons , Li Xiao , Simon C. Benjamin , Jonathan A. Jones

An ideal system of $n$ qubits has $2^n$ dimensions. This exponential grants power, but also hinders characterizing the system's state and dynamics. We study a new problem: the qubits in a physical system might not be independent. They can…

Quantum Physics · Physics 2018-10-19 Rui Chao , Ben W. Reichardt , Chris Sutherland , Thomas Vidick

We present an implementation of Kuang and Bettenburg's Quantum Permutation Pad (QPP) used to encrypt superposition states. The project was conducted on currently available IBM quantum systems using the Qiskit development kit. This work…

Quantum Physics · Physics 2023-02-21 Maria Perepechaenko , Randy Kuang

Quantum Signal Processing (QSP) is a technique that can be used to implement a polynomial transformation $P(x)$ applied to the eigenvalues of a unitary $U$, essentially implementing the operation $P(U)$, provided that $P$ satisfies some…

Quantum Physics · Physics 2023-03-21 Lorenzo Laneve