The Deutsch-Jozsa algorithm is one of the first examples of a quantum algorithm that is exponentially faster than any possible deterministic classical algorithm. It was proposed by Deutsch and Jozsa in 1992 with improvements by Cleve, Ekert, Macchiavello, and Mosca in 1998. The Deutsch-Jozsa problem is a promise problem and we can equivalently describe it as a partial function ${\text{DJ}}_{n}^{0}:{{0,1}}^{n}\ensuremath{\rightarrow}{0,1}$ defined as ${\text{DJ}}_{n}^{0}(x)=1$ for $|x|=n/2, {\text{DJ}}_{n}^{0}(x)=0$ for $|x|=0,n$ , and it is undefined for the rest of the cases, where $n$ is even, and $|x|$ is the Hamming weight of $x$ . The optimal quantum algorithm needs only one query to compute ${\text{DJ}}_{n}^{0}$ but the classical deterministic algorithm requires ${2}^{n\ensuremath{-}1}+1$ queries to compute it in the worse case. In this article, we generalize the Deutsch-Jozsa problem as ${\text{DJ}}_{n}^{k}(x)=1$ for $|x|=n/2, {\text{DJ}}_{n}^{k}(x)=0$ for $|x|$ in the set ${0,1,...,k,n\ensuremath{-}k,n\ensuremath{-}k+1,...,n}$, and it is undefined for the rest of the cases, where $0\ensuremath{\le}k<n/2$. In particular, we give and prove an optimal exact quantum query algorithm with complexity $k+1$ for computing the generalized Deutsch-Jozsa problem ${\text{DJ}}_{n}^{k}$ . It is clear that the case of $k=0$ is in accordance with the Deutsch-Jozsa problem. Also, we give a method for finding the approximate and exact degrees of symmetric partial Boolean functions.The Deutsch-Jozsa algorithm is one of the first examples of a quantum algorithm that is exponentially faster than any possible deterministic classical algorithm. It was proposed by Deutsch and Jozsa in 1992 with improvements by Cleve, Ekert, Macchiavello, and Mosca in 1998. The Deutsch-Jozsa problem is a promise problem and we can equivalently describe it as a partial function ${\text{DJ}}_{n}^{0}:{{0,1}}^{n}\ensuremath{\rightarrow}{0,1}$ defined as ${\text{DJ}}_{n}^{0}(x)=1$ for $|x|=n/2, {\text{DJ}}_{n}^{0}(x)=0$ for $|x|=0,n$, and it is undefined for the rest of the cases, where $n$ is even, and $|x|$ is the Hamming weight of $x$. The optimal quantum algorithm needs only one query to compute ${\text{DJ}}_{n}^{0}$ but the classical deterministic algorithm requires ${2}^{n\ensuremath{-}1}+1$ queries to compute it in the worse case. In this article, we generalize the Deutsch-Jozsa problem as ${\text{DJ}}_{n}^{k}(x)=1$ for $|x|=n/2, {\text{DJ}}_{n}^{k}(x)=0$ for $|x|$ in the set ${0,1,...,k,n\ensuremath{-}k,n\ensuremath{-}k+1,...,n}$, and it is undefined for the rest of the cases, where $0\ensuremath{\le}k<n/2$. In particular, we give and prove an optimal exact quantum query algorithm with complexity $k+1$ for computing the generalized Deutsch-Jozsa problem ${\text{DJ}}_{n}^{k}$. It is clear that the case of $k=0$ is in accordance with the Deutsch-Jozsa problem. Also, we give a method for finding the approximate and exact degrees of symmetric partial Boolean functions.

Physical Review AJun 20, 201831 citations

Entanglement tensor for a general pure multipartite quantum state

Hoshang Heydari, Gunnar G. Bjork

In the black-box model, problems constrained by a `promise' are the only ones that admit a quantum exponential speedup over the best classical algorithm in terms of query complexity. The most prominent example of this is the Deutsch-Jozsa algorithm. More recently, Wim van Dam put forward an algorithm for unstructured problems (i.e., those without a promise). We consider the Deutsch-Jozsa algorithm with a less restrictive (or `broken') promise and study the transition to an unstructured problem. We compare this to the success of van Dam's algorithm. These are both compared with a standard classical sampling algorithm. The Deutsch-Jozsa algorithm remains good as the problem initially becomes less structured, but the van Dam algorithm can be adapted so as to become superior to the Deutsch-Jozsa algorithm as the promise is weakened.In the black-box model, problems constrained by a `promise' are the only ones that admit a quantum exponential speedup over the best classical algorithm in terms of query complexity. The most prominent example of this is the Deutsch-Jozsa algorithm. More recently, Wim van Dam put forward an algorithm for unstructured problems (i.e., those without a promise). We consider the Deutsch-Jozsa algorithm with a less restrictive (or `broken') promise and study the transition to an unstructured problem. We compare this to the success of van Dam's algorithm. These are both compared with a standard classical sampling algorithm. The Deutsch-Jozsa algorithm remains good as the problem initially becomes less structured, but the van Dam algorithm can be adapted so as to become superior to the Deutsch-Jozsa algorithm as the promise is weakened.

Quantum Information and ComputationMay 1, 20057 citations

Generalized Quantum Deutsch-Jozsa Algorithm

Tomasz Arodź

Lecture notes in computer scienceJan 1, 20201 citation

Complexity Beyond Classical Limits: A Study of Quantum Query and Communication Models

Daiki Suruga

Mar 25, 20250 citations

Temperature change can solve the Deutsch-Jozsa problem: An exploration of thermodynamic query complexity

Jake Xuereb

We demonstrate how a single heat exchange between a probe thermal qubit and multiqubit thermal machine encoding a Boolean function can determine whether the function is balanced or constant, thus providing a thermodynamic solution to the Deutsch-Jozsa problem. We introduce a thermodynamic model of quantum query complexity, showing how qubit thermal machines can act as oracles, queried via heat exchange with a probe. While the Deutsch-Jozsa problem requires an exponential encoding in the number of oracle bits, we also explore a restricted Bernstein-Vazirani problem, which admits a linear thermal oracle and a single thermal query solution. We establish bounds on the number of samples needed to determine the probe temperature encoding the solution for the Deutsch-Jozsa problem, showing that it remains constant with problem size. Additionally, we propose a proof-of-principle experimental implementation to solve the three-bit Bernstein-Vazirani problem via thermal kickback. This work bridges thermodynamics and complexity theory, suggesting that quantum thermodynamics could provide an unconventional route to computing beyond classical computation.We demonstrate how a single heat exchange between a probe thermal qubit and multiqubit thermal machine encoding a Boolean function can determine whether the function is balanced or constant, thus providing a thermodynamic solution to the Deutsch-Jozsa problem. We introduce a thermodynamic model of quantum query complexity, showing how qubit thermal machines can act as oracles, queried via heat exchange with a probe. While the Deutsch-Jozsa problem requires an exponential encoding in the number of oracle bits, we also explore a restricted Bernstein-Vazirani problem, which admits a linear thermal oracle and a single thermal query solution. We establish bounds on the number of samples needed to determine the probe temperature encoding the solution for the Deutsch-Jozsa problem, showing that it remains constant with problem size. Additionally, we propose a proof-of-principle experimental implementation to solve the three-bit Bernstein-Vazirani problem via thermal kickback. This work bridges thermodynamics and complexity theory, suggesting that quantum thermodynamics could provide an unconventional route to computing beyond classical computation.

arXiv:2505.15887Physical Review ADec 4, 20250 citations

{\text{DJ}}_{n}^{0}(x)=1

for

|x|=n/2, {\text{DJ}}_{n}^{0}(x)=0

for

|x|=0,n

, and it is undefined for the rest of the cases, where

n

is even, and

|x|

is the Hamming weight of

x

. The optimal quantum algorithm needs only one query to compute

{\text{DJ}}_{n}^{0}

but the classical deterministic algorithm requires ${2}^{n\ensuremath{-}1}+1$ queries to compute it in the worse case. In this article, we generalize the Deutsch-Jozsa problem as

{\text{DJ}}_{n}^{k}(x)=1

for

|x|=n/2, {\text{DJ}}_{n}^{k}(x)=0

for

|x|

in the set ${0,1,...,k,n\ensuremath{-}k,n\ensuremath{-}k+1,...,n}$, and it is undefined for the rest of the cases, where $0\ensuremath{\le}k<n/2$. In particular, we give and prove an optimal exact quantum query algorithm with complexity

k+1

for computing the generalized Deutsch-Jozsa problem

{\text{DJ}}_{n}^{k}

. It is clear that the case of

k=0

is in accordance with the Deutsch-Jozsa problem. Also, we give a method for finding the approximate and exact degrees of symmetric partial Boolean functions.