A new record for atom-based quantum computers: 1,000 atomic qubits and rising

Phys.org  February 15, 2024 Researchers in Germany designed a large-scale quantum-processing architecture surpassing the tier of 1000 atomic qubits. By tiling multiple microlens-generated tweezer arrays, each operated by an independent laser source, they eliminated laser-power limitations in the number of allocatable qubits. With two separate arrays, they implemented combined 2D configurations of 3000 qubit sites with a mean number of 1167(46) single-atom quantum systems. The transfer of atoms between the two arrays effectively. Supercharging one array designated as the quantum processing unit with atoms from the secondary array significantly increased the number of qubits and the initial filling fraction. They […]

Discovery may enable network interface for quantum computers

Phys.org  October 5, 2023 The coupling of microwave and optical systems presents a challenge due to the natural incompatibility of energies, but potential applications range from optical interconnects for quantum computers to next-generation quantum microwave sensors, detectors, and coherent imagers. Emerging platforms are constrained by specific conditions. An international team of researchers (Poland, Denmark) designed a set-up using Rydberg atoms that allows wideband coupling of optical and microwave photons at room temperature. They demonstrated continuous-wave conversion of a 13.9 GHz field to a near-infrared optical signal using an ensemble of Rydberg atoms via a free-space six-wave mixing process designed to minimize […]

How splitting sound might lead to a new kind of quantum computer

Phys.org  July 5, 2023 Linear optical quantum computing provides a desirable approach to quantum computing, with only a short list of required computational elements. The similarity between photons and phonons points to the interesting potential for linear mechanical quantum computing using phonons in place of photons. Although single-phonon sources and detectors have been demonstrated, a phononic beam splitter element remains an outstanding requirement. Researchers at the University of Chicago demonstrated such an element, using two superconducting qubits to fully characterize a beam splitter with single phonons. They used the beam splitter to demonstrate two-phonon interference, a requirement for two-qubit gates […]

Microsoft claims to have achieved first milestone in creating a reliable and practical quantum computer

Phys.org.  June 24, 2023 Researchers at Microsoft (USA) engineered a new way to represent a logical qubit with hardware stability. They reported that the device could induce a phase of matter characterized by Majorana zero modes, such devices have demonstrated low enough disorder to pass the topological gap protocol, proving the technology is viable. They stated that it has created a new measure to gauge the performance of a quantum supercomputer: reliable quantum operations per second (rope), a figure that describes how many reliable operations a computer can execute in a single second. They suggest that for a machine to […]

A blueprint for a quantum computer in reverse gear

Phys.org  May 4, 2023 If two integers are entered as the input value, the computer circuit returns their product. Researchers in Austria developed inversion of algorithms with the help of quantum computers. The logic of the circuit was encoded within ground states of a quantum system. Both multiplication and factorization could be understood as ground-state problems and solved using quantum optimization methods. The core of their work was the encoding of the basic building blocks of the multiplier circuit, specifically AND gates, half, and full adders with the parity architecture as the ground state problem on an ensemble of interacting […]

Absolute zero in the quantum computer: Formulation for the third law of thermodynamics

Phys.org  April 4, 2023 Nernst’s unattainability principle states that infinite resources are required to cool a system to absolute zero temperature. An international team of researchers (Japan, Austria, Sweden, France, Denmark, Switzerland, Ireland, Brazil, Germany) provided a framework for identifying the resources that enable the creation of pure quantum states. They showed that perfect cooling is possible with Landauer energy cost given infinite time or control complexity. However, optimal protocols required complex unitaries generated by an external work source. Restricting to unitaries that can be run solely via a heat engine, they derived a novel Carnot-Landauer limit, along with protocols […]

Electrons zip along quantum highways in new material

Nanowerk  November 9, 2022 An international team of researchers (USA – University of Chicago, Pennsylvania State University, Israel) discovered a new material, MnBi6Te10, which could be used to create quantum highways useful in connecting the internal components of energy-efficient quantum computers. In the ferromagnetic phase, an energy gap of 15 meV was resolved at the Dirac point on the MnBi2Te4 termination. In contrast, antiferromagnetic MnBi6Te10 exhibited gapless topological surface states on all terminations. Measurements revealed substantial Mn vacancies and Mn migration in ferromagnetic MnBi6Te10. They provided a conceptual framework where a cooperative interplay of these defects drove a delicate change […]

Unimon – A new qubit to boost quantum computers for useful applications

Nanowerk  November 15, 2022 Superconducting qubits seem promising for useful quantum computers, but the currently wide-spread qubit designs and techniques do not yet provide high enough performance. Researchers in Finland have developed a superconducting-qubit type, the unimon, which combines the desired properties of increased anharmonicity, full insensitivity to dc charge noise, reduced sensitivity to flux noise, and a simple structure consisting only of a single Josephson junction in a resonator. In agreement with their quantum models, they measured the qubit frequency and increased anharmonicity at the optimal operation point. It yielded, 99.9% and 99.8% fidelity for 13 ns single-qubit gates on […]

A Huge Step Forward in Quantum Computing Was Just Announced: The First-Ever Quantum Circuit

Science Alert  June 22, 2022 Researchers in Australia have created a functional quantum processor and tested it by modeling a small molecule in which each atom has multiple quantum states. They used a scanning tunneling microscope in an ultra-high vacuum to place quantum dots with sub-nanometer precision. The trickiest parts were figuring out: exactly how many atoms of phosphorus should be in each quantum dot; exactly how far apart each dot should be; and then engineering a machine that could place the tiny dots in exactly the right arrangement inside the silicon chip. The final quantum chip contained 10 quantum […]

Using two different elements creates new possibilities in hybrid atomic quantum computers

Nanowerk  March 2, 2022 Researchers at the University of Chicago have introduced a dual-element atom array with individual control of single rubidium and cesium atoms. They were placed in arrays with up to 512 trapping sites and observed negligible crosstalk between the two elements. Furthermore, by continuously reloading one atomic element while maintaining an array of the other, they demonstrated a new continuous operation mode for atom arrays without any off-time. According to the researchers the results enable avenues for auxiliary-qubit-assisted quantum protocols such as quantum nondemolition measurements and quantum error correction, as well as continuously operating quantum processors and […]