A Quantum Leap for Silicon Chips: Spin-Photon Coupling Now a Reality
March 6, 2018 | CORDISEstimated reading time: 2 minutes
Quantum theory began to take shape over a century ago and has since been the focus of many studies and observations. Yet, it’s only in recent years that scientists began to envision the use of quantum mechanics in technology, and more specifically in computing. TU Delft, the university hosting the QC-LAB project, has joined the race to build efficient quantum computers, with significant results.
The quantum phenomena that allow us to speak of revolutionising the world of computers as we know it are superposition and entanglement. In a classical computer, a bit can have one of two values: a one or a zero. In a quantum computer, the basic unit of information, known as a quantum bit, or qubit, can be a one, a zero, or both a one and a zero at the same time. This condition of being in multiple possible states is known as superposition.
As qubits are added to a computer, its power increases exponentially. But, to benefit from this increase in power, qubits need to be linked, even if they are separated by a large distance. This phenomenon is referred to as quantum entanglement.
The Computer of the Future
By harnessing phenomena such as superposition and entanglement, tomorrow’s quantum computers will be able to solve problems that would take current mainframe computers countless years to do, such as factorising large prime numbers or searching extensive unsorted data sets.
However, for a quantum computer to be able to make such useful computations, it would require lots of qubits, and it’s precisely this need for large numbers of qubits that poses a challenge. These fragile units of quantum information must be able to communicate well if these computers are to be a success.
The Promise of Silicon
Quantum chips store information in qubits and are made of silicon. Widely used in electronic devices, silicon makes lengthy storage of information possible and therefore holds promise as a quantum technology material. But, scientists have yet to figure out how to increase the number of physics (spin) qubit systems. As described in their paper published in the journal ‘Science’, the project’s researchers have taken a step towards addressing this issue by showing that a single electron spin and a single microwave photon can be coupled on a silicon chip. In the authors’ own words, ‘[t]he electron spin is trapped in a silicon double quantum dot and the microwave photon is stored in an on-chip high-impedance superconducting resonator.’ They add: ‘The electric field component of the cavity photon couples directly to the charge dipole of the electron in the double dot, and indirectly to the electron spin, through a strong local magnetic field gradient from a nearby micromagnet.’ Researchers said that their results provide a route to realising large networks of quantum dot-based spin qubit registers.
This quantum chip with reliable silicon qubits is an important milestone on the road to achieving scalable quantum calculations. The QC-LAB team’s goal is to develop a 13-qubit circuit that will demonstrate back-and-forth quantum state transfer between qubits.
Suggested Items
Stan Rak: Elevating the Ideas and Insights of IPC's Thought Leaders Program
04/25/2024 | Stanton Rak, SF Rak CompanyAs a member of the IPC Thought Leaders Program (TLP), I am responsible for identifying knowledge-sharing opportunities that can generate ideas and insights that strengthen the IPC community as well as create a sustainable and lasting future for its members. I am delighted to highlight some of my recent contributions as a member of the TLP.
indie Semiconductor Launches Advanced Smart Connectivity Solutions for In-Cabin Applications
04/23/2024 | indie Semiconductorindie Semiconductor, Inc., an Autotech solutions innovator, has introduced a family of new high-performance video converters and retimers to enable in-cabin connectivity applications, including audio and video transport and device interfacing.
The Need for a Holistic Global Sustainability Standard
04/10/2024 | Michael Ford, Aegis SoftwareNo one can deny that the resources of our fragile planet are finite. The environment seems like a third party, subject to constant degradation. We’re acutely aware of the effects of pollution on our climate, and despite our “throw-away” culture, recycling and recovery of materials has remained relatively expensive, even as we use more energy just to survive.
Technica Leads the Way Into Automation and Machine Learning at IPC APEX EXPO 2024
03/28/2024 | Marcy LaRont, PCB007 MagazineAs a significant partner to PCB fabricators since almost the beginning of multilayer boards, Technica USA brings a lot of expertise to the industry. This year’s IPC APEX EXPO show will showcase their biggest booth yet, and a whole lot of information, discussion and demonstration around automation and AI machine learning. In this interview, Jason Perry discusses Technica's plans for the show, and why attendees should stop by.
Airbus to Acquire INFODAS and Strengthen its Cybersecurity Portfolio
03/25/2024 | AirbusAirbus Defence and Space has entered into an agreement to acquire INFODAS, a Cologne-based, German company that provides cybersecurity and IT solutions in the public sector including for defence and critical infrastructures.