A major breakthrough has been achieved in the development of diamond-based quantum computers.
Quantum computers and quantum communication are groundbreaking technologies that enable faster and more secure data processing and transmission compared to traditional computers. In quantum computers, qubits serve as the fundamental units of information, functioning as the quantum mechanical equivalent of bits in classical computing.
Where, for example, laser pulses in a glass fiber transport information from A to B in classical digital communication, quantum mechanics uses individual photons. In principle, this makes it impossible to intercept the transmitted data. Qubits that are optically addressable (can be controlled or read out with light) are suitable for storing the photons’ information and processing it in quantum computers. The qubits can store and process quantum states, and absorb and emit them in the form of photons.
Qubit Stability Is Key
A major challenge in qubit development is extending the coherence time, i.e. the time in which qubits can store information in a stable manner. Being able to control qubits and keep them stable enough to exploit their characteristics in practical applications will be crucial to the feasibility of developing efficient and scalable quantum computers.
At KIT’s Physikalisches Institut, doctoral researchers Ioannis Karapatzakis and Jeremias Resch have investigated how to precisely control a special defect in diamonds known as a tin-vacancy (SnV) center. Their work was part of two projects funded by Germany’s Federal Ministry of Education and Research: QuantumRepeater.Link (QR.X) for secure fiber-based quantum communication and SPINNING, which aims to develop a diamond spin-photon-based quantum computer.
“A defect in the lattice structure of a diamond’s carbon atoms occurs when atoms are missing or are replaced by other atoms such as tin,” said Karapatzakis. Such defects can be used as qubits for quantum communication because they have special optical and magnetic properties that enable states such as their electron spin to be manipulated using light or microwaves. The defects can then be used as stable qubits that can store and process information and couple it with photons.
Considerable Improvement in Coherence Times
Diamond qubits have the advantage of existing in the solid phase, making them easier to work with than other quantum materials, e.g. atoms in a vacuum. Karapatzakis and Resch were able to precisely and observably control the electron spins of tin-vacancy center qubits using microwaves. “We were able to increase the coherence times of the diamond SnV centers to as long as ten milliseconds – a major improvement,” says Resch.
They did so with dynamical decoupling, which largely suppresses interference. A further special aspect of the researchers’ results is their success in demonstrating for the first time that this type of diamond defect can be very efficiently controlled with superconducting waveguides, which efficiently direct microwave radiation to the defects without generating heat.
“That’s very important because these defects are generally investigated at very low temperatures near absolute zero. Higher temperatures would make the qubits useless,” says Karapatzakis.
“To establish communication between two users or (later) between two quantum computers, we need to transfer the qubit quantum states to photons,” notes Resch. “With optical readout of qubits and by reaching stable spectral properties, we’ve taken an important step in that direction. So our results on controlling tin-vacancy centers in diamonds offer the potential for an important breakthrough in the future development of secure and efficient quantum communication.”
Reference: “Microwave Control of the Tin-Vacancy Spin Qubit in Diamond with a Superconducting Waveguide” by Ioannis Karapatzakis, Jeremias Resch, Marcel Schrodin, Philipp Fuchs, Michael Kieschnick, Julia Heupel, Luis Kussi, Christoph Sürgers, Cyril Popov, Jan Meijer, Christoph Becher, Wolfgang Wernsdorfer and David Hunger, 27 August 2024, Physical Review X.
DOI: 10.1103/PhysRevX.14.031036
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3 Comments
Quantum computers and quantum communication are groundbreaking technologies that enable faster and more secure data processing and transmission compared to traditional computers.
VERY GOOD.
When physics uses imagined things as the Formal Base and Evidential Base for research. What is the difference between physics and religion?
Scientific research guided by correct theories can help people avoid detours, failures, and exaggeration. The physical phenomena observed by researchers in experiments are always appearances, never the natural essence of things. The natural essence of things needs to be extracted and sublimated based on mathematical theories via appearances , rather than being imagined arbitrarily.
Everytime scientific revolution, the scientific research space brought by the new paradigm expands exponentially. Physics should not ignore the analyzable physical properties of topological vortices.
(1) Traditional physics: based on mathematical formalism, experimental verification and arbitrary imagination.
(2) Topological Vortex Theory: Although also based on mathematics (such as topology), it focuses more on non intuitive geometry and topological structures, challenging traditional physical intuition.
Topological Vortex Theory points out the limitations of the Standard Model in describing the large-scale structure of the universe, proposes the need to consider non-standard model components such as dark matter and dark energy, and suggests that topological vortex fields may be key to understanding these phenomena. Topological vortex research reflections on the philosophy and methodology of science help us understand the nature essence of science and the limitations of scientific methods. This not only has guiding significance for scientific research itself, but also has important implications for science education and popularization.
Topological vortex theory heralds innovative technologies such as topological electronics, topological smart batteries, topological quantum computing, etc., which may bring low-energy electronic components, almost inexhaustible currents, and revolutionary computing platforms, etc.
Topology tells us that topological vortices and antivortices can form new spacetime structures via the synchronous effect of superposition, deflection, or twisting of them. In fact, mathematics does not tell us that there must be God particles, ghost particles, fermions, or bosons present. When physics and mathematics diverge, arbitrary imagination will make physics no different from theology.
Today, so-called official (such as PRL, Nature, Science, PNAS, etc.) in physics stubbornly believes that two sets of cobalt-60 rotating in opposite directions can become two sets of objects that mirror each other, is a typical case that pseudoscience is rampant and domineering. Please witness the exemplary collaboration between theoretical physicists and experimentalists (https://scitechdaily.com/microscope-spacecrafts-most-precise-test-of-key-component-of-the-theory-of-general-relativity/#comment-854286).
Let us continue to witness together the dirtiest and ugliest era in the scientific and humanistic history of human society. The laws of nature will not change due to misleading of so-called academic publications.
Ask the researchers:
1. Do you understand the natural essence of quantum?
2. Is quantum a cat that is both dead and alive?
3. Is the topological vortex left-handed or right-handed?
4、Can topological vortices generate gravitation?
5、Is there a correlation between topological vortices and so-called gravitons?