How close can we get to the fundamental limits of quantum computation? This study investigates a spin-encoded quantum computer operating near the Landauer bound and Heisenberg limit. It showcases that the Doppler temperature manifests the existence of Landauer’s bound, which does not block a spin from (irreversibly) flipping with a tiny amount of energy via quantum tunneling. The minimum energy required for irreversible quantum operations is explored, revealing experimental results close to the theoretical Landauer’s bound. Based on Heisenberg’s principle, we defined information from a measuring perspective: one bit of information corresponds to the smallest error when quantifying the product of the measured energy uncertainty (ΔE) and the measured time duration (Δt). Furthermore, a new definition of information is proposed based on Heisenberg’s principle, linking it to the minimum error in quantifying energy and time duration. The study then illustrates an optically manipulated, spin-encoded, near-Landauer-bound, near-Heisenberg-limit quantum computer that encompasses this new definition of information. The single spin is the smallest information carrier and that was used in the test. This study may represent the last piece of the puzzle in understanding both quantum Landauer erasure and Heisenberg’s quantum limit since a single spin is the smallest information carrier. By pushing the boundaries of quantum computation to their physical limits, this research contributes to a deeper understanding of the fundamental principles governing information processing at the quantum scale.
This research aligns with the focus of Quantum Information Processing by exploring fundamental limits in quantum computation. The study's investigation of spin-encoded quantum computers and their proximity to the Landauer bound and Heisenberg limit is directly relevant to the journal's scope.