Practical Guide to Using a Quantum Computer (Based on Materials from the International Quantum Center at CERN, Switzerland) - #1

Abstract This laboratory work provides a practical introduction to the use of a quantum computer, based on educational materials developed by the International Quantum Center at CERN (Switzerland). The objective of the first laboratory session is to familiarize users with the quantum computing environment, fundamental circuit construction, and the interaction between quantum and classical registers. In Laboratory Work No. 1, a basic quantum circuit is configured using the IBM Quantum cloud platform. The system consists of a single quantum bit (qubit), denoted as q0, and a single classical bit, denoted as c4. The experiment demonstrates the initialization of a qubit, the construction of a simple quantum circuit, and the measurement process that maps a quantum state onto a classical bit. Through this hands-on implementation, participants gain an operational understanding of quantum state preparation, measurement postulates, and the hybrid quantum-classical computational workflow. The guide emphasizes practical interaction with real quantum hardware and simulators, allowing users to observe probabilistic measurement outcomes and understand the physical interpretation of quantum superposition and state collapse. By bridging theoretical quantum mechanics and executable quantum circuits, this laboratory work lowers the barrier to entry for students and researchers transitioning from classical programming paradigms to quantum computation.