Microsoft unveils Majorana 1 as a quantum leap
Quantum computing has leaped with giant strides towards solving the imponderables! Topological qubits with a new core, powers Majorana 1, the world’s first quantum processor, which is built with a yet newer class of material called topoconductor. It is being hailed as a breakthrough due to its unique ability to pave a way for quantum systems, scaling up to millions of cubits.
Qubits being the basic building blocks of computing, will solve problems which are beyond the solving capacities of the current generation of computers. According to Satya Nadella, CEO of Microsoft, all the world’s computers clubbed together might not be able to do what Majorana 1 is capable of. An entirely new state of matter has been created which will be years ahead in solving meaningful, industrial-scale problems.
Nadella added, “imagine a chip that can fit in the palm of your hand yet is capable of solving problems that even all the computers on earth today combined could.” And he added again, “entirely new state of matter (created), unlocked by a new class of materials, topoconductors, that enable a fundamental leap in computing. (And) this is apart from the existing states of matter – solid, liquid, and gas.”
A statement from Microsoft says that the new type of material, which has been harnessed and engineered, is a radically different type of qubit that is small, fast, and digitally controlled.
Quantum computers as a tool for useful computing
While Quantum computers are on the path to transform science and society, they have to achieve a scale, hitherto unreachable throughout these years. Their reliability is ensured by a quantum error correction, leading to useful computing.
The Microsoft statement further adds that a path from a single-qubit device to arrays that enable quantum error correction, means a device roadmap to reliable quantum computation.
As part of the final phase of Defense Advanced Research Projects Agency (DARPA) Underexplored Systems for Utility-Scale Quantum Computing (US2QC) program, Microsoft is going to build a File Transfer Protocol (FTP) of a scalable computer, that too, in a few years. An advancement in technological innovation from mere scientific exploration is a pivotal moment earmarked by these milestones.
The new revolutionary material, harnessed namely, the topoconductor is a new state of matter which, till now, existed only in theory. In the said system, innovations in design and fabrication of gate-defined devices combining indium arsenide (a semiconductor) and aluminum (a superconductor) have been produced.
Topological superconducting nanowires are formed upon cooling the above materials to near absolute zero when tuned with magnetic fields, with Majorana Zero Modes (MZMs) at the wires’ ends. Creating and controlling these quasiparticles on demand is easier now in the topoconductors, according to Microsoft.
Storing quantum information via parity, these MZMs are the building blocks of qubits, notwithstanding a presence of even or an odd electron number. In today’s superconductors, electrons move without resistance due to their binding into Cooper pairs and can be detected due to the necessity of large energy reserves in applications.
The topoconductors are different as an unpaired electron is shared between an MZM pair, thus rendering it invisible. Quantum information is thus protected by this unique property. Despite the latest breakthrough, reading the hidden quantum information isn’t easy in case of a possible error, like distinguishing between 1,000,000,000 and 1,000,000,001 electrons.
As the error probability of 1% in the initial measurements is very much a possibility, the solution has been affected by means of many steps in succession. A quantum dot, a tiny semiconductor device storing electrical charge, is coupled with both ends of a nanowire using the digital switches. Increasing the dot’s exact ability to hold charge nevertheless, depends upon the nanowire parity.
The charge is measured, utilizing microwaves and then the dot ability to charge is determined upon reflection of the former. The imprint of the nanowire quantum state is revealed upon the return of these microwaves. The shielding enveloping the processor, developed by scientists, is effective as it ensures the exclusion of radiation, avoiding Cooper pair breakages.
In the absence of any shielding, creation of unpaired electrons happens due to electromagnetic radiation where they can flip the qubit’s state from even to odd parity. Further reduction of these parities is being explored. The quantum control has been ensured through digital precision, which includes connecting and disconnecting quantum dots from the nanowires.
This is a part of the measurement-based approach simplifying quantum error correction (QEC). Complex analog control signals used in the traditional computing method involve rotating quantum states through precise angles. These signals are customized for each qubit, complicating the QEC which relies on the sensitive processes for error detection and correction.
Large numbers of qubits needed for real-world applications are managed by the development of this digital control. Single-qubit device called tetron is in the offing and uses the same technique as described in ra esearch-based paper, Nature.
