Embarking on a Journey to Quantum Computing — Without Physics Degree

Andi Sama
6 min readNov 30, 2021

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Qubit, An Intuition — An Introduction to Quantum Computing, featuring IBM Quantum

Andi Sama CIO, Sinergi Wahana Gemilang with Cahyati S. Sangaji

TL;DR;
- A starting point on the practical technical foundation for quantum enthusiasts and the community who do not have a background in Quantum Physics, such as the authors. The intention is to provide sufficient practical technical knowledge and understanding to play a role and contribute to this exciting field.
- A summary of six published June-December 2021's articles in the "Quantum, An Intuition" series, with reference links.
- Getting to know and having initial intuition on Quantum Computing by understanding the basic mechanics of working with qubits, the quantum bits.

Well, it's December 2021, and finally, we have completed all six articles in the "Qubit, An Intuition" series. Our main intention in developing the series has been to provide a sound practical technical introduction to quantum computation for non-quantum-physicists and non-mathematicians to start their journey in Quantum Computing.

Schrödinger's Cat — A Thought Experiment illustrating Superposition
Put a cat in a box with decaying radioactive material and a Geiger counter.
The radioactive can decay and emit alpha particles at a random time. Geiger counter can then generate electrons to energize the hammer to smash open the flask containing deadly gas (TheInformationPhilosopher, 2021).
Schrödinger’s cat thought experiment illustrates superposition in which a particle (an electron, for example) behaves like a wave when not observed and has multiple linear combinations of different states at the same time (e.g., |Alive> and |Dead> at the same time). However, when we perform an observation (e.g., measurement), the wave function |Cat> collapses to either |Alive> or |Dead> state according to a probability distribution of the system.It is important to note that superposition only applies to the microscopic world (particles) like atoms, electrons, photons, and the like. It does not apply to the macroscopic world, such as a cat in the above illustration.

Following several sessions of online educations, reading books, attending multiple online conferences, experimenting with IBM Quantum, and sharing with colleagues, we think it is time to contribute what we have been learning to quantum enthusiasts and the community.

For those interested, please visit the article on my journey in Quantum Computing, "My Journey to Quantum Computing" (Andi Sama, 2021c).

To me personally, early exposure to advanced & emerging technologies has been one of my realized passion in the last ten years like Cloud, Big data, Internet of Things (IoT), blockchain, and Artificial Intelligence that have been the key drivers in the 2010s. Quantum Computing is an exciting new emerging technology area, promising a leap forward over Classical Computing towards 2030 and beyond.When I started to learn Quantum Computing in early 2020, I found Quantum Computing has been really challenging. My educational background in computer engineering (bachelor’s degree) and computer science & business administration (master’s degrees) do not seem to provide enough foundation knowledge for learning Quantum Computing. Thus, it’s a long journey towards an exciting future.

We published the first article in medium on July 12, 2021, "Qubit, An Intuition #1: First Baby Steps in Exploring the Quantum World." Then, we published a few follow-on articles monthly. In the end, we published the final article on Dec 6, 2021, "Qubit, An Intuition #6: Two Famous Quantum Algorithms, Shor's and Grover Algorithms."

The six published June-December 2021's articles in the "Quantum, An Intuition" series. The infographics template by (Infographics Presentation Template, 2021).

We summarize all the links, referring to all six articles in the series as follow:

  1. "Qubit, An Intuition #1 — First Baby Steps in Exploring the Quantum World" discusses a single qubit as a computing unit for quantum computation.
The typical workflow in a hybrid Classical-Quantum computation: prepare a quantum circuit (classical), submit the quantum circuit to a quantum computer through provided APIs, process the quantum circuit (quantum), return the quantum measurement for post-processing (classical).

2. "Qubit, An Intuition #2 — Inner Product, Outer Product, and Tensor Product" discusses two-qubits operations in bra-ket notation, with examples

Bra-ket notation for two-qubit operations. The operations are expressed in the inner product, outer product, and tensor product.

3. "Qubit, An Intuition #3 — Quantum Measurement, Full and Partial Qubits" illustrates several examples of full and partial quantum measurements.

A two-qubits state |Ψ>.
The probabilities and resultant states to measure two-qubit states 00, 01, 10, and 11 are 16%, 48%, 9%, and 27%.

4. "Qubit, An Intuition #4 — Unitary Matrices for Quantum Computation" discusses unitary matrices with examples and their implementation in IBM quantum.

The X (NOT), H (Hadamard), Z, and CNOT gates in IBM Quantum on IBM Cloud.

5. "Qubit, An Intuition #5 — Quantum Circuit and Reversible Transformation" discusses reversible transformations in the quantum circuits, quantum circuits written as unitary matrices, and the execution of the quantum circuit on IBM Quantum.

Reversible operations in a quantum circuit. After performing U conjugate transpose, the output quantum state |Ψ'> returns to |Ψ>. An online tool, Quirk, created the illustration.

6. "Qubit, An Intuition #6 — Two Famous Quantum Algorithms, Shor's and Grover Algorithms" illustrates Shor's quantum factoring and Grover's quantum search algorithms and their implementation in IBM Quantum.

The time complexity comparison graph for classical factoring and Shor's quantum algorithms (The graph is created by an online tool). Shor's search quantum algorithm promises a polynomial-time.

We would be glad if the "Quantum, An Intuition" series could serve as one of the starting points on the practical technical foundation for quantum enthusiasts and the community who do not have a background in Quantum Physics, such as the authors. The intention is to provide sufficient practical technical knowledge and understanding to play a role and contribute to this exciting field.

One of the potential applications is in Quantum Machine Learning (QML). An early illustration for an image classification use-case is doing transfer learning from the pre-trained model, applied to classify a person with or without the mask.

The commercialization of quantum use cases can be broadly categorized into three areas (Andi Sama, 2021a): Machine Learning, Simulation, and Optimization.

  • Machine Learning creates models to predict the outcome, given sufficient historical data. Quantum Machine Learning is possible, e.g., by doing transfer learning in which part of the trained model which has been trained classically is optimized with a quantum computer.
  • Quantum chemistry simulation that performs quantum simulation on finding the suitable catalyst (that does not require high temperature) for chemical reactions can significantly improve new material discovery in material science. Likewise, molecular biology and healthcare research (e.g., drug discovery) include a process similar to chemistry research. In this case, quantum simulations can replace laboratory experiments.
  • Optimization aims to minimize or maximize a given objective function, given constraints. Optimization can reduce travel distance in a logistic network or maximize capacity and system throughput to avoid conflicts and backlogs.

In addition to quantum computing applications, other use potential use cases like quantum sensing (e.g., for medical imaging and GPS-free navigation starting in 2025) and quantum communication (e.g., quantum internet towards 2035).

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