Optimal Stochastic Resource Allocation for
Distributed Quantum Computing
Napat Ngoenriang∗, Minrui Xu†, Sucha Supittayapornpong∗, Dusit Niyato†, Han Yu†, Xuemin (Sherman) Shen‡
∗School of Information Science and Technology, Vidyasirimedhi Institute of Science and Technology, Thailand
†School of Computer Science and Engineering, Nanyang Technological University, Singapore
‡Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON, Canada
Abstract—With the advent of interconnected quantum com-
puters, i.e., distributed quantum computing (DQC), multiple
quantum computers can now collaborate via quantum networks
to perform massively complex computational tasks. However,
DQC faces problems sharing quantum information because it
cannot be cloned or duplicated between quantum computers.
Thanks to advanced quantum mechanics, quantum computers
can teleport quantum information across quantum networks.
However, challenges to utilizing efficiently quantum resources,
e.g., quantum computers and quantum channels, arise in DQC
due to their capabilities and properties, such as uncertain qubit
fidelity and quantum channel noise. In this paper, we propose
a resource allocation scheme for DQC based on stochastic pro-
gramming to minimize the total deployment cost for quantum re-
sources. Essentially, the two-stage stochastic programming model
is formulated to handle the uncertainty of quantum computing
demands, computing power, and fidelity in quantum networks.
The performance evaluation demonstrates the effectiveness and
ability of the proposed scheme to balance the utilization of
quantum computers and on-demand quantum computers while
minimizing the overall cost of provisioning under uncertainty.
Index Terms—Distributed Quantum Computing, Quantum
Networks, Resource Allocation, Stochastic Programming
I. INTRODUCTION
To date, quantum computing is tremendously fast and effi-
cient, being able to do computations in a matter of seconds
which would take decades for older supercomputers [1]. In
2019, a prototype of Google’s quantum computer was able to
finish the computation and demonstrate the effectiveness of
quantum mechanics [2]. Breakthroughs in quantum comput-
ing are essential and influence various applications, such as
artificial intelligence (AI), molecular modelling, weather fore-
casting, and drug development [3]. Since the development of
quantum computers is still in its infancy, distributed quantum
computing (DQC) has emerged in significance to solve more
complex computational tasks. In the next quantum computing
era, IBM [4] and Google [5] aim to introduce a practical DQC,
which is anticipated in 2025. Although the advent of DQC has
also advanced processing speed for a variety of heterogeneous
tasks, quantum resources are still limited and need to be
managed effectively while performing computations.
The basis for the development of quantum computing is
formed based on properties of quantum mechanics, i.e., super-
position, entanglement, and interference, as shown in Fig. 1.
Superposition permits encoding in a mixture of two states
(i.e., qubits). A qubit offers more information storage and
computation choices than binary bits in classical computers.
In quantum mechanics, entanglement describes a correlation
between two qubits in which the values of one qubit may
depend on another. To observe the values of qubits, measure-
ment, often referred to as interference, can be used to interrupt
the processing of quantum computers.
Quantum algorithms enable qubits in quantum computers
by utilizing quantum mechanics. For instance, Shor’s [6]
and Grover’s [7] algorithms were developed to deal with
factorization and the search for unstructured data, respectively,
which are highly challenging for classical computers. To tackle
these tasks with quantum computers, at least the order of 106
physical qubits are required [6]. However, a recently devel-
oped quantum computer can only contain tens of qubits [8].
Therefore, it becomes increasingly challenging to handle and
control information in quantum computers due to the limited
number of qubits, the instability of qubits, and the amount of
information required for complex computational tasks. As a
result, the concept of DQC has been presented.
In DQC, quantum teleportation, or the transfer of qubits, is
required for quantum computers to connect and collaborate.
In this regard, multiple quantum computers can work col-
laboratively to compute a large-scale complex computational
task at quadratic or exponential speed-up. Moreover, most of
common quantum algorithms can benefit from their distributed
equivalents. For example, distributed Shor’s algorithm can
reduce computational complexity compared to original Shor’s
algorithm [9]. Additionally, distributed Grover’s algorithm has
a considerably lower query time than Grover’s algorithm [10].
Therefore, distributed quantum algorithms can enhance prac-
tical feasibility of quantum computers in tackling complex
computational tasks in practice.
Although DQC and distributed quantum algorithms have
evolved and accelerated to handle complex computational
tasks, quantum resources, e.g., quantum computers and quan-
tum channels, must be optimally allocated to perform hetero-
geneous computational tasks. However, the efficient utilization
of quantum resources in DQC is still facing challenges.
First, the utilization of quantum resources depends on the
demands of computational tasks, which are not known pre-
cisely at the time of quantum computer deployment. Second,
quantum computers’ availability and computing power may
arXiv:2210.02886v1 [cs.DC] 16 Sep 2022