What is Quantum Machine Learning?

Parth Shukla 06 Feb, 2024 • 6 min read


Machine learning is one of the trending topics in the current industry and business scenarios, where almost all companies and businesses want to integrate machine learning applications into their working mechanisms and work environments. It is growing daily, and its application is enhancing time by time, where many scientists and students are working on the research of the same.

Quantum computing has been a hot topic recently and has more comprehensive applications than regular classical computers. This article will discuss quantum machine learning, which integrates quantum computing and machine learning. We will discuss its working, application, and some of the advantages and disadvantages associated with it. This article will help one to understand the new topic and will help to plan and learn accordingly.

Before directly jumping to the concept, let us discuss quantum computing first.

Learning Objectives

This article will help one to:

  • To understand the core idea behind quantum computing
  • Difference between the three types
  • How it works?
  • Applications of the machine learning
  • Answer interview questions related to quantum machine learning

This article was published as a part of the Data Science Blogathon.

What is Quantum Computing?

Quantum computing is a branch of computer science that uses the quantum physics concepts to solve problems and statements that regular or classical computers can’t solve. Like the bits in the classical computers, the quantum computer uses qubits capable of solving complex problems and passing the information to each other.


Here, qubits surpass standard bits found in classical computers in terms of sophistication and data storage capabilities. Additionally, qubits can be conceptualized as specific waves in quantum physics responsible for containing and transmitting information and data.

It is better to compare classical and quantum machine learning to get a clear idea. However, before comparing them, let us compare normal programming and machine learning.

Types of Quantum Machine Learning

Quantum machine learning combines quantum algorithms and machine learning techniques to improve the speed and accuracy of learning from data. It uses quantum physics and quantum computers to enhance the capabilities of machine learning. There are different types of quantum machine learning, such as:

Quantum Neural Networks (QNN)

These are neural networks that operate on quantum logic gates and qubits, which are the basic units of quantum information. QNNs can leverage quantum phenomena such as superposition and entanglement, enabling qubits to simultaneously exist in multiple states and exhibit correlation with each other. QNNs can perform faster and more efficient learning than classical neural networks.

Quantum Support Vector Machines (QSVM)

These are support vector machines that use quantum algorithms to find the optimal hyperplane that separates the data points into different classes. QSVMs can use quantum speedup and quantum parallelism, which enable quantum computers to perform multiple operations simultaneously and solve complex problems faster than classical computers.

Quantum Reinforcement Learning (QRL)

These are reinforcement learning algorithms that use quantum agents and quantum environments to learn optimal policies and actions. QRL can use quantum resources and quantum feedback, which provide quantum agents with more information and better rewards than classical agents.

    Applications of Quantum Computing

    1. More Faster Algorithms

    With the help of quantum computing, we can make the algorithm’s training on more enormous datasets faster and more efficient. The QML algorithms can be super faster compared to classical machine learning where qubits will play major role.

    2. Solving Complex Data Patterns

    Quantum computing can assist in solving complex data patterns that cannot be addressed by classical machine learning and deep learning algorithms. Very complicated datasets where data correlations and patterns are not recognisable and solvable, the QML can make it possible.

    3. Develop Advanced Algorithms

    Quantum computing, with the integration of machine learning can help build and design more advanced machine learning algorithms. Advanced algorithms integrated with quantum computing can solve more problems in less times with greater accuracies.

    4. Advancement in Reinforcement Learning

    Reinforcement learning stands to benefit significantly from the incorporation of quantum computing concepts. Novel concepts within reinforcement learning can be developed and enhanced through quantum machine learning utilizing qubits.

    5. Advanced Computer Vision

    Quantum machine learning can also help advance the computer vision application and make the existing deep learning algorithms quicker and more efficient. With the help of quantum machine learning, we can develop more advanced and accurate image segmentation and processing applications.

    Classical Programs vs. Machine Learning

    As we might think that machine learning is the same as classical programming, it is wrong. In classical programming, the input is taken, preprocessed, and then directed to the output is given. Here we have pre-defined functions and rules where we take the information, apply functions and regulations to it, and whatever result we get, we display it as an output of the program.

    Machine learning is very different from classical programming, where the input is first divided into two parts, training and testing. Then the training data is fed to the machine learning program where no pre-defined function exists in the rules. The model learns from the training data autonomously, and after training, it undergoes testing with the actual values from the testing data. The loss function aids in identifying the errors and mistakes made by our model.

    As we saw that machine learning is entirely different than the classical programming, now let us compare.

    Machine Learning vs. Quantum Machine Learning

    As we discussed that machine learning is a set of program that takes the data as input, preprocess it, and learn from it. Then, the testing data is used to evaluate the model, and the model’s loss is calculated.

    Quantum Machine Learning

    We take the ideas of atoms and molecules from quantum physics and train the model on training data rather than the bits level. In quantum machine learning, we utilize qubits, which are far more advanced than regular bits. We also test the model on the testing data after its training, calculate the loss function, and try to minimize the same.

    What Exactly is Quantum Machine Learning?

    Now as we have an idea about classical programming, machine learning, and quantum computing, it is the best time to learn about QML. This process entails integrating classical machine learning with quantum computing, leveraging quantum computing to apply machine learning concepts and techniques instead of relying solely on classical computing and programs.

    Quantum Machine Learning

    As the standard or classical computer works with bits with either the value 0 or 1, the same quantum computers have qubits or quantum bits, which also store the data. Still, it leverages the principle of superposition, which means that, unlike the classical bits, the qubit can be in multiple states simultaneously.

    To understand the principle of superposition, let us take an example. We have a coin. We toss it, and now it can give us a tail or a head. Before launching the cos’s or while the coin is flipping in the air, we can’t say it’s in a heads or tails state. That means it is partially in heads and tails, according to the person’s view. The principle referred to here is called the superposition of the coin, where the coin can exist in multiple states simultaneously.


    This article discussed quantum machine learning and how it differs from classical programming and machine learning. This article will help one understand the concept, its core idea, and how it can be helpful in the future.

    Some of the key takeaways are as follows:

    1. In classical programming, we just take the input, process it and display the output with the help of pre-defined functions.
    2. Machine learning is an advanced approach to classical programming where the model learns from the data and results from an output.
    3. In QML, we use machine learning with quantum computing concepts, where we employ qubits instead of bits to train the model.
    4. QML can help in making the existing algorithms faster, developing new algorithms, and solving more complex algorithms.

    The media shown in this article is not owned by Analytics Vidhya and is used at the Author’s discretion.

    Parth Shukla 06 Feb 2024

    UG (PE) @PDEU | 25+ Published Articles on Data Science | Data Science Intern & Freelancer | Amazon ML Summer School '22 | AI/ML/DL Enthusiast | Reach Out @portfolio.parthshukla.live

    Frequently Asked Questions

    Lorem ipsum dolor sit amet, consectetur adipiscing elit,

    Responses From Readers

    Related Courses

    0 Hrs 23 Lessons

    Dimensionality Reduction for Machine Learning


    0 Hrs 261 Lessons

    Machine Learning Certification Course for Beginners-2


    0 Hrs 261 Lessons

    Machine Learning Certification Course for Beginners


    • [tta_listen_btn class="listen"]