The following list of projects for the SQA Undergraduate Research Scholarships are offered across the four SQA partner universities. Applicants must indicate their top three project preferences on their application form. Read more to apply

Note to applicants: In each project there are details on student suitability, however, please do not let this discourage you from any project that interests you.

### Project 1: Robust control of IBM quantum devices (A/Prof Daniel Burgarth)

*University:* Macquarie University*School or Department:* Physics*Faculty*: Science

*Student suitability:* 3rd-year physics, computer science, mathematics or engineering student with experience in Python.

You will look at the superconducting quantum physics which underlies the IBM cloud quantum computer and identify the largest sources of noise, which prevent such machines from beating classical supercomputers at the moment. You will then numerically develop optimal control pulses which fight this noise. Potentially you will test the pulses on the real quantum computer (pending access).

### Project 2: Optimisation of coplanar waveguide circuits for superconducting quantum devices (Dr Juan Pablo Dehollain)

*University:* University of Technology Sydney*School or Department:* Mathematical and Physical Sciences*Faculty*: Science

*Secondary or co-supervisor:* Dr Nathan Langford*Student suitability:* 2nd-year physics or higher

In this project, the students will use state-of-the-art electromagnetic simulation software to study the performance of novel coplanar waveguide designs, particularly in the context of superconducting microwave resonators used in cutting-edge quantum devices. The student will use Python-based machine learning packages to optimise circuits for signal response parameters and compact design. As part of this project, the student will have the opportunity to learn about microwave electromagnetic simulations for quantum circuit design and simple machine-learning techniques.

### Project 3: Characterisation of oxide quality for silicon quantum dot devices (Prof Andrew Dzurak)

*University:* University of New South Wales*School or Department:* Electrical Engineering & Telecommunications*Faculty*: Engineering*Secondary or co-supervisor:* Wee Han Lim*Student suitability:* 3rd year engineering or physics students

Due to their similarity to conventional CMOS devices and their ability to leverage existing industrial technology and know-how, quantum dot devices in silicon hold immense potential for the realisation of full-scale quantum computers. In these MOS quantum devices, the quantum dots are formed by accumulating carriers against the Si/SiO2 interface, and therefore the properties of this interface can influence the behaviour of the quantum dots. This project aims to further our understanding of the properties of the oxide interface, which is critical to the development of these MOS devices. The student will measure Hall effect devices in cryogenic test setups to determine properties of the interface, such as the mobility and carrier density in order to extract oxide parameters relevant to quantum device operation.

### Project 4: Electrostatic modelling of silicon qubit devices (Dr Chris Escott)

*University:* University of New South Wales*School or Department:* Electrical Engineering & Telecommunications*Faculty*: Engineering

*Secondary or co-supervisor:* Andre Saraiva*Student suitability:* 3rd year engineering or physics students

Adapting industrial CMOS technology to silicon-CMOS quantum dot qubit device fabrication is a promising road towards full-scale quantum computers. Devices currently used for successful demonstration of 1- and 2-qubit gates possess strong similarities to conventional CMOS devices, by making use of biasing gates to accumulate electrons at the Si/SiO2 interface. Understanding the influence of the electrode/gate geometry and the biasing configuration in many-electrode devices is paramount to further improvements in device design and control. This project will require the student to simulate the electrostatics of silicon quantum dot devices to capture the influence of biasing, design, cryogenic operation and real-world imperfections. The simulations will be performed with a mix of industry standard and bespoke tools to accurately describe the behaviour of the quantum dot devices.

### Project 5: Realizing Gottesman-Kitaev-Preskill codes with Floquet engineering (Dr Arne Grimsmo)

*University:* The University of Sydney*School or Department:* Physics*Faculty*: Science*Secondary or co-supervisor:* Raditya Bomantara*Student suitability:* 3rd year physics student with advanced quantum mechanics knowledge and an interest in quantum error correction and fault-tolerance

We will investigate ways to robustly prepare Gottesman-Kitaev-Preskill codewords in a harmonic oscillator using periodically driven Hamiltonians.

### Project 6: Semiconductor hole spin qubits (Professor Alex Hamilton)

*University:* University of New South Wales*School or Department:* Physics*Faculty*: Science*Secondary or co-supervisor:* Dr. Scott Liles / Matthew Rendell / Dr. Feixiang Xiang*Student suitability:* 2nd and 3rd year Physics or Engineering students who have covered quantum physics

Our understanding of the quantum mechanical properties of positively charged holes in nanoscale electronic devices is far from complete, despite the fact that your mobile phone contains billions of transistors that use holes. This is because although undergraduates are often taught that valence band holes are essentially just heavy electrons, with a positive charge and a positive effective mass, holes are spin-3/2 particles whereas electrons are spin-1/2. The spin-3/2 nature of holes means they make excellent spin quantum bits, and this project will involve hands on laboratory research to study how to read and manipulate hole spin qubits. See http://www.phys.unsw.edu.au/QED for more details.

### Project 7: Quantum transport in 2D Topological materials (Professor Alex Hamilton)

*University:* University of New South Wales*School or Department:* Physics*Faculty*: Science*Secondary or co-supervisor (if any):* Dr. Scott Liles / Matthew Rendell / Dr. Feixiang Xiang*Student suitability:* 2nd and 3rd year Physics or Engineering students who have covered quantum physics

There is enormous interest in the science of topological two-dimensional (2D) materials, as these can support dissipationless electronic transport. We have two projects related to topological systems, either created in conventional semiconductors or by using Van der Waals heterostructures (built using the Nobel prize winning sticky tape technique which exploits the strong van der Waals interaction between atomically smooth surfaces, allowing the creation of new layered materials from few-atom thick building blocks). The robustness and performance of the topological states are being tested with computer controlled electrical transport measurements down to ultracold temperatures and high magnetic fields.

### Project 8: Flip-chip bonding development for cryogenic device assembly (Dr Fay Hudson)

*University:* University of New South Wales*School or Department:* Electrical Engineering & Telecommunications*Faculty*: Engineering*Secondary or co-supervisor:* Ross Leon*Student suitability:* 3rd year engineering students

Silicon-based quantum dot devices hold good prospects for scaled quantum information processing systems, however there are still challenges to solve in scaling from the current few-qubit systems up to the many qubits required for logical qubit operation. As the number of electrical connections grows, assembly and packaging requirements become increasingly complicated. This project aims to develop a flip-chip bonding process to enable high density connections between the silicon quantum device and the measurement apparatus. The student will be required to develop a test board, work with process engineers to develop the flip-chip bonding process and test the viability of the bonds in standard cryogenic test setups.

### Project 9: Simulating chemical dynamics on trapped ions (A/Prof Ivan Kassal)

*University:* The University of Sydney*School or Department:* Chemistry*Faculty*: Science*Student suitability:* Physics or chemistry student with some exposure to quantum mechanics. No chemistry knowledge is required. Computer programming experience is helpful, but not required.

We have recently shown that trapped-ion quantum computers could use their vibrational degrees of freedom as a computational resource to dramatically speed up the simulation of chemical reaction dynamics. We expect that our approach may lead to one of the first practical uses of quantum computers by using existing quantum technologies to solve chemical problems that are beyond the scope of current classical supercomputers.

In this theory project, you could expand the scope of our approach in several ways, to make for a general-purpose simulation scheme. Possible topics include incorporating the role of anharmonic interactions, understanding the impact of experimental noise, developing control techniques to suppress imperfections, or working with our experimental colleagues in Prof. Biercuk's lab to analyse their results on a proof-of-principle simulation.

### Project 10: Optimise microwave cryogenic wiring design for dilution refrigerators (Dr Nathan Langford)

*University:* University of Technology Sydney*School or Department:* Mathematical and Physical Sciences*Faculty*: Science*Secondary or co-supervisor:* Dr JP Dehollain*Student suitability:* This project would be suitable for a 2nd-year or higher physics or engineering students.

In this project, the student will study the different heat load effects of cryogenic wiring on microwave and cooling performance in a dilution refrigerator. They will develop a numerical model in Python that incorporates a range of different effects and use the model to determine optimal working parameters for the cryogenic wiring installation in our new state-of-the-art fridges. If time permits, they will begin to design key hardware components to be manufactured for installing and thermalising the wiring. In carrying out this project, the student will learn about dilution refrigerator operation, cryogenic and microwave design, and important electronic control considerations for quantum experiments.

### Project 11: Interfacing quantum chip design with EM simulation software using Python (Dr Nathan Langford)

*University:* University of Technology Sydney*School or Department:* Mathematical and Physical Sciences*Faculty*: Science*Secondary or co-supervisor:* Dr JP Dehollain*Student suitability:* 3rd year or higher Physics / Engineering students or 2nd year or higher Computer Science students

In this project, the student will work with researchers in the Langford lab to develop new python-based device-design software package that is used to design superconducting electronics circuits for quantum chips and PCB sample interfaces. Specifically, the student will help develop a software driver to interface the chip-design software with state-of-the-art electromagnetic simulation software packages, like CST, that are critical for designing the performance parameters of state-of-the-art quantum devices. The students will use the interface to design and test a simple PCB sample interface. As part of this project, the student will learn in-demand professional coding skills like git version control, collaborative and modular coding methods, and test-driven development.

### Project 12: Digital quantum simulation of the dispersive quantum Rabi model phase transition (Dr Nathan Langford)

*University:* University of Technology Sydney*School or Department:* Mathematical and Physical Sciences*Faculty*: Science*Secondary or co-supervisor:* Dr Arne Grimsmo*Student suitability:* This project would be suitable for a 3rd-year physics student (or 3rd-year maths student with some quantum background).

In this project, the student will numerically study the quantum phase transition in the quantum Rabi model with an additional dispersive interaction term. Using a Python-based quantum dynamics simulation software suite developed in the Langford lab, the student will study the ideal model and a digital quantum simulation in a circuit QED realisation. The student will model the system using physically realisable parameters and study dynamical performance signatures that could be realised in an experiment. In carrying out this project, the student will receive an introduction into key considerations for implementing digital quantum simulations in circuit QED systems.

### Project 13: Measuring the superconductivity of thin films (Dr Arne Laucht)

*University:* University of New South Wales*School or Department:* Electrical Engineering & Telecommunications*Faculty*: Engineering

*Secondary or co-supervisor:* Ross Leon*Student suitability:* 3rd year physics or engineering students

Silicon-based quantum devices are promising candidates for full-scale universal quantum computing, owing to their similarity to conventional CMOS devices. In order to realise the potential of this technology, understanding the cryogenic properties of constituent materials is vital. Superconducting materials can be used in qubit systems for applications ranging from long-distance qubit coupling via microwave cavities to high-quality resonators for gate-dispersive readout circuits. This project involves cryogenic measurements of thin metallic films to determine their conductivity as a function of temperature to find materials with suitable superconductive properties for applications in silicon qubit architectures.

### Project 14: Grating design for a Neurophotonic platform (A/Prof Stefano Palomba)

*University:* The University of Sydney*School or Department:* Physics*Faculty*: Science*Secondary or co-supervisor:* Alessandro Tuniz*Student suitability:* 2nd and 3rd-year physics student

It is well known that genetically modified photoactive neurons can be differentiated from pluripotent embryonic stem cells (ESC).

In this project we need to model high-index waveguides with in- and output gratings to send/collect light to/from the immobilised photoactive synapses. The project outcome will deliver the geometrical parameters necessary for fabricating and testing these photonic chips.

### Project 15: Self-assembled plasmonic nanostructures (A/Prof Stefano Palomba)

*University:* The University of Sydney*School or Department:* Physics*Faculty*: Science

*Secondary or co-supervisor (if any):* Alessandro Tuniz*Student suitability*: 2nd and 3rd-year physics student

In collaboration with the School of Biomedical Engineering, we are aiming to optically characterise various Self-assembled plasmonic (metallic) nanostructures which exhibit unpublished optical properties. Such self-assembled structure could have applications in biosensing, linear, nonlinear and quantum optics. This is a fully experimental project.

### Project 16: Atomistic Modelling of Quantum Defects in Semiconductors (A/Prof Rajib Rahman)

*University:* University of New South Wales*School or Department:* Physics*Faculty*: Science*Student suitability:* 2nd year physics and above

The project aims to develop atomistic tight-binding models of defects and impurities in several popular semiconductors for quantum technologies. The defect species include vacancies in Silicon Carbide and Diamond, as well as magnetic and charge defects in III-V and group IV semiconductors. Simulations will be done with our in-house NEMO3D tool in a supercomputing platform. Adequate tutorials are available for a quick start.

### Project 17: Atomistic simulation of Majorana nanowires (A/Prof Rajib Rahman)

*University:* University of New South Wales*School or Department:* Physics*Faculty*: Science*Student suitability:* 2nd year physics and above

The project aims to simulate several III-V material nanowires with the atomistic tight-binding method to understand interface states and the role of spin-orbit and confinement. The simulations will be done in our in-house NEMO3D tool and several material species such as InAs, GaSb, and InSb will be explored. The simulations will investigate the atomistic interfaces of superconducting and semiconducting materials and investigate the impact of strain and electric fields on quasi-particle wavefunctions.

### Project 18: Nonlinear Quantum Walks (Dr Alexander Solntsev)

*University:* University of Technology Sydney*School or Department:* Mathematical and Physical Sciences*Faculty*: Science*Student suitability:* Final-year physics student, experience with Matlab, optics and quantum mechanics

Quantum walks have emerged as a powerful paradigm with applications in quantum search. In 2020, the development of new experimental platforms in photonics enabled large scale quantum walks with simultaneous generation of walkers (entangled photons) through nonlinear optics. The general theoretical framework has been developed by our group. Now we need to find interesting regimes through analysis and numerical modelling, which will form the basis of the project.

### Project 19: Improving Quantum Measurement in a Trapped-Ion Quantum Computer (Dr Ting Rei Tan)

*University:* The University of Sydney*School or Department:* Physics*Faculty*: Science

*Secondary or co-supervisor:* Michael Biercuk*Student suitability:* 3rd-year Physics Student

One of the most promising architectures for quantum computation and the simulation of other, less accessible quantum systems is based on trapped atomic ions confined by electric potentials in an ultra- high vacuum environment. Record coherence times and the highest operational fidelities among all qubit implementations have enabled remarkable progress in recent years and, with the only two fully- operational systems in Australia, the quantum control laboratory works at the forefront of research in this area. This project seeks to improve the quality of quantum state measurement in ytterbium ion qubit by employing experimental quantum control technique and explore novel machine-learning scheme based on knowledge on the atomic energy level properties. Project involves laboratory works including laser optics and microwave systems, as well as complementary software programming and numerical simulations.

### Project 20: Conservation laws, relativistic processes and qubits (A/Prof Daniel Terno)

*University:* Macquarie University*School or Department:* Physics & Astro*Faculty*: Science & Engineering*Secondary or co-supervisor:* Prof Gavin Brennen*Student suitability:* 3rd y/honours students with either (A) a primary interest in quantum information that want to know how its optical implementation is affected by relativity, or (B) high-energy/particle physics students who are interested in quantum-informational side of the relativistic physics

Photons created in electron-positron annihilation are used in medical imaging and studies of quantum foundations, and electron-positron pairs are produced in strong laser fields. We know how to map polarization of photons to states of qubits, and all early demonstrations of quantum information protocols are based on it. However, there are several groups of questions that still has to be answered by combining results from entanglement theory and relativistic quantum mechanics (and, for some of the questions, QED): What are limitations and possibilities when we take into account conservation laws (momentum, angular momentum, parity)? What are restrictions on possible types of multi-partite entanglement with photons? How the entanglement can be swapped from photons to antiparticles and vice versa?