Ion quantum technology opportunities at Sussex
Quantum theory can have powerful applications due to the possibility of implementing new quantum technologies such as the quantum computer. While such a device could have very important commercial and national security applications due to the existence of quantum factoring algorithms, its existence would revolutionize modern day science by allowing true quantum simulations of systems that may be modelled classically only insufficiently due to an in-principle limitation of current computer technology. Recent developments in ion trapping technology show that it should be possible to build a quantum computer with trapped ions. At Sussex we pursue the quest to build a quantum computer, an effort that will be based in Sussex but include links to nanofabrication facilities, ion trapping groups and theorists around the world.
A three-year PhD position is available in the Ion Quantum Technology Group in the Department of Physics & Astronomy at the University of Sussex. It is in conjunction with an EPSRC funded £1.4M Leadership fellowship for the development of quantum technology with nanofabricated ion trap chips.
Research in novel quantum technologies will likely lead to step changing innovations which will affect many areas of modern sciences. Implementing such technologies with trapped ions quantum bits has been widely accepted as one of the most promising pathways. The aim of this studentship is to produce advanced nano-fabricated ion chips and to carry out entanglement experiments with trapped ions in order to build a practical ion trap quantum computer.
One of the main aims of the project is to develop ion chips that feature on-chip digital signal processing and specialized architectures for large scale entanglement generation. Furthermore, you will also carry out studies to implement on-chip cavities, fibre interconnects to the ion trap array for advanced ion quantum state detection capabilities and other advanced features. You will create microchips for large scale entanglement creation of trapped ions on a chip. Once suitable ion chips are available you will carry out entanglement experiments and create practical quantum simulators.
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You can find out more about the group here (including a BBC documentary about our research group):
The ‘Research’ section of the website features specific information for prospective PhD students. You can also take a virtual lab tour.
Detailled reading about some of our research directions can be found here:
- Microfabricated Ion Traps, Marcus D. Hughes, Bjoern Lekitsch, Jiddu A. Broersma and Winfried K. Hensinger, Contemporary Physics 52, 505 (2011)
- Microwave ion-trap quantum computing, Winfried K. Hensinger, Nature 476, 155 (2011)
Please contact Dr.Winfried Hensinger for more information.
To apply please email a CV, and your degree results preferentially before 20/12/12 to the email address above. Note in order to qualify for this position you must have resided in the UK or Europe for three years prior to the start of the position. If you are from outside Europe, you may apply for a non-funded position in the group, however, you will need to have a source for tuition fees and living expenses.
1. Laser cooling of ytterbium ions
Trapping single atoms is being described as one of the most demanding experiments in atomic physics. This project includes experimental work in trapping and cooling single ions towards the realization of an ion trap quantum computer. You will learn about laser cooling of ytterbium ions. Furthermore, you will study ways how to cool the ions to the quantum mechanical ground state. This project includes both theoretical and experimental parts. You will learn how to align lasers onto the ion trap, operation of a laser locking scheme, and the handling of a complicated imaging system as well as studying the theoretical foundations of how to manipulate ions using lasers. Your work should leads towards the experimental realisation of ground state cooling with trapped ions.
2. Lasers and laser locking for trapping ytterbium ions
Trapping ytterbium ions requires a number of lasers all operating at the required frequency to perform cooling and trapping of ytterbium ions. As part of this project you learn about the lasers required and construct a new laser that will be used for the ion trapping experiments. You will also learn about laser locking and build a laser locking scheme that allows for much higher laser stability. This is a prerequisite for efficient entanglement and detection capabilities.
3. Advanced ion chips
For large scale quantum computing to occur large scale ion trap arrays need to be designed that allow optimal storage, shuttling and entanglement operations to be performed. The arrays are constructed within an integrated microchip. In this project you will study how to add advanced features to ion chips such as digital signal processing, on-chip cavities, fibre connects along with on-chip resistors and capacitors. In addition, you will devise recipes for the application of microwaves on the chip and the implementation of magnetic field gradients. You will identify important issues in nanofabrication of ion traps and address such challenges with advances in condensed matter physics.
4. Exploring optimal ion trap geometries
At Sussex, we are actively researching optimal in trap geometries for the implementation of large scale ion trap chips. This project will investigate different ion trap geometries and model different ion trap junction types. The aim is to find optimal geometries for shuttling, storing and manipulating single ions. Shuttling of single atomic ions that are used as quantum bits for a quantum computer is a complicated process and we need to understand how single ions can be efficiently separated from another, turn corners and be decelerated using optimal geometries for this purpose. Electromagnetic field simulations will determine the ion trapping characteristics of different trap geometries. In this project you will research such optimal ion trap geometries and find scaling laws to understand such geometries in depth.
5. Shuttling trapped ions inside arrays
In our group we develop advanced ion trap arrays on a chip. In order to transport ions through such an array of electrodes the motion of the ion has to be carefully controlled. This project investigates how ions can be carefully shuttled in such an ion trap array without changing their motional quantum state. You will investigate optimal ways to transport individual ions and develop voltage sequences that are applied to multiple electrodes in order to move ions along a line, transport them through a junction or separate ions that are part of an ion string.
6. Entanglement creation and quantum simulators
Quantum technology, particularly quantum computing relies on the ability to entangle ions. Entanglement has been referred by Einstein as “spooky” and is one of the most counterintuitive predictions of quantum physics. In order to create ion entanglement here at Sussex optimal ion quantum gates must be identified and the ion trap experiment must be modified to allow for entanglement gates. This may involve some theory, programming and experimental work. You will also evaluate how to increase gate fidelities in order to reduce error rates within quantum computing operations.
7. Communicating quantum technology
A famous quantum physicist once proclaimed that the only physicists who understand quantum physics are the ones who know that they don’t understand it. Within this project you will analyze the factors that lead to the difficulty in obtaining an intuitive understanding of quantum physics. Once these factors become clear, you will devise strategies to circumvent such problems and create a strategy to communicate quantum technology research to a number of different target groups such as the general public, A-level Students and undergraduate physics Students. You will then create appropriate materials such as websites, simulations, applets, handouts and hand-on demonstrations in order effectively communicate quantum technology research. You will also measure the efficiency of the created strategy and materials by analyzing its effect on various target groups. Experience in making websites and interactive simulations would be very useful.
8. Ion quantum technology
Open topic, anything that you would want to investigate which falls under the general heading of ion quantum technology.
Please contact Dr.Winfried Hensinger for more information. A number of scholarship schemes are available for Students from the University of Sussex and its Sepnet partners (University of Kent, Queen Mary / University of London, Royal Holloway / University of London, University of Southampton, University of Surrey). Note that there is no financial support available for Students who do not carry out their undergraduate program at the University of Sussex or any of the SEPnet partner universities
Ion trap quantum information science is a fastly growing field with many opportunities. We currently have an opening for a postdoctoral position. More details can be found here. If you are interested, please contact Dr.Winfried Hensinger for more information.