Shuo Sun obtained his Bachelor of Science in 2011 with a specialization in optics at Zhejiang University in China. He received his M. S. (2015) and Ph.D. (2016) in the Department of Electrical and Computer Engineering from University of Maryland, College Park while working with Professor Edo Waks in the area of quantum optics and quantum information. He has been awarded for the grand prize of the Maiman student paper competition (2015) and department distinguished dissertation award (2016) for his pioneering work on experimental demonstrations of a solid-state spin-photon quantum switch. He started as a postdoctoral research scholar at Stanford University in 2017, working with Professor Jelena Vuckovic in the Ginzton Laboratory on defect color center based quantum nanophotonic devices.
Honors & Awards
Chinese Government Award for Outstanding Self-Financed Students Abroad, Chinese Government (2016)
Distinguished Dissertation Award, Department of Electrical and Computer Engineering, University of Maryland (2016)
Grand Prize of Maiman Outstanding Student Paper Competition, OSA (2015)
Chu Kochen Award (highest honor for undergraduate students at Zhejiang University), Zhejiang University (2011)
Grand Prize of China Instrument and Control Society Scholarship, China Instrument and Control Society (2011)
Doctor of Philosophy, University of Maryland College Park (2016)
Master of Science, University of Maryland College Park, Electrical and Computer Engineering (2015)
Bachelor of Science, Zhejiang University (2011)
Jelena Vuckovic, Postdoctoral Faculty Sponsor
Current Research and Scholarly Interests
My general research interest is to develop quantum technology based on nanoscale photonic devices for applications in quantum computation, communication, and sensing.
During my Ph.D., my research focused on on realizing fundamental quantum hardware using quantum dots coupled to photonic crystal cavities (see "Projects" below for detailed descriptions of our research). Quantum dots are semiconductor nanocrystals that are engineered to behave as an atom. They can trap electrons and holes, which have spin degree of freedom that are very suitable for storing and processing quantum information. Spins of charged quantum dots are promising candidates for developing integrated quantum circuits and on-chip quantum processors, because they are embedded in a semiconductor substrate and the technology for integration with modern electronics already exists.
The highlight of the research in my Ph.D. is that we demonstrated the first quantum transistor between a single solid-state qubit (realized by a quantum dot spin) and a photon. This transistor operates at the most fundamental level, where single quanta of light (photons) and single entities of matter (qubits) switch each other. This work is the culmination of over a decade of advances in the preparation and control of solid-state spin and generation of strong light-matter interactions in nanophotonic devices, and represents the most advanced step towards compact solid-state quantum networks and on-chip quantum circuits.
I have recently joined Professor Jelena Vuckovic's group as a postdoctoral research scholar, trying to explore new and emerging materials that hold great promise to overcome many of the challenges facing solid-state quantum information processing, and to build more complex quantum devices and quantum networks with nanophotonic tools. Especially, we are interested in investigating quantum optical properties of Silicon Vacancy (SiV) centers in diamond. Recent works have shown that these color centers have very promising properties including long electronic coherence time, strong emission to the zero-phonon-line, narrow inhomogeneous broadening, and no spectral diffusion. I am currently working on realizing quantum devices with SiV centers, as well as investigating cavity quantum electrodynamics involving multiple nearly identical emitters using these solid-state emitters.
Quantum dot spin based quantum logic devices (Experiment and Theory)
The elementary unit of a modern computer is an electronic transistor, which switches one digital signal based on the state of the second one. Here the state of the digital signal is called a "bit", which can only occupy one of the two possible states: logic high ("1") and logic low ("0"). In our research, we try to realize a fundamental building block for a quantum computer, for example, a quantum transistor which switches one quantum bit (often referred as "qubit") based on the state of a second qubit. Here the qubit is realized by a physical system that obeys the laws from quantum mechanics, which can not only occupy "0" and "1" states, but also any arbitrary superposition states between "0" and "1". This weird feature of quantum mechanics promises unprecedented computational ability and communication security for a quantum information system.
We realize quantum logic devices on the quantum dot platform. Quantum dots are semiconductor nanocrystals that are engineered to behave as an atom. They can trap electrons and holes, which have spin degree of freedom that are very suitable for storing and processing quantum information. The quantum dot spin qubits are promising for developing integrated quantum circuits and on-chip quantum processors, because they are embedded in a semiconductor substrate and the technology for integration with modern electronics already exists. Through our research, we demonstrated the first quantum transistor between a single solid-state qubit and a photon. This transistor operates at the most fundamental level, where single quanta of light (photons) and single entities of matter (qubits) switch each other. This work is the culmination of over a decade of advances in the preparation and control of solid-state spin and generation of strong light-matter interactions in nanophotonic devices, and represents the most advanced step towards compact solid-state quantum networks and on-chip quantum circuits. Since the photon is an ideal transit carrier for quantum information, our efforts could eventually lead to scalable and integrated quantum processors where photons interconnect multiple quantum dot spin qubits.
A quantum phase switch between a single solid-state spin and a photon, Shuo Sun, Hyochul Kim, Glenn S. Solomon, and Edo Waks, Nature Nanotechnology 11, 539-544 (2016).
Deterministic generation of entanglement between a quantum-dot spin and a photon, Shuo Sun and Edo Waks, Physics Review A 90, 042322 (2014).
University of Maryland, College Park
Cavity enhanced optical readout of a single solid-state spin (Experiment and Theory)
The ability to projectively measure the state of a qubit with high accuracy is crucial for nearly all quantum information processing applications. For example, quantum computing requires the ability to read out the states of all output qubits after the quantum algorithm completes, and quantum cryptography requires readout of all transmitted qubits. Currently, optical spin readout provides one of the fastest and most precise methods for spin readout, making it a promising approach for scalable quantum information processing.
Previous approaches for optical qubit readout reply on either resonance fluorescence spectroscopy or optical Kerr or Faraday effect. However, all previous approaches require a cycling transition where an excited state optically couples to only one of the qubit basis states. These readout methods do not work for qubit systems that lack a cycling transition such as spins of singly charged quantum dots or silicon vacancy centers.
In this work, we propose and experimentally demonstrate a novel approach for optical spin readout based on cavity quantum electrodynamics. We optically detect the spin of a charged quantum dot by measuring the reflectivity of a cavity that is strongly coupled to one quantum state of the spin. We observe significant improvement in the qubit readout fidelity. Our method is broadly applicable to many qubit systems including quantum dot spins, silicon vacancy centers in diamond, and fluorine impurities in CdTe, and may also be useful for lots of new and emerging qubit systems that are still under developed. It shows how tailoring light-matter interactions opens up new possibilities for processing quantum information with higher speed and accuracy.
Single-shot optical readout of a quantum bit using cavity quantum electrodynamics, Shuo Sun and Edo Waks, Physical Review A 94, 012307 (2016).
Cavity enhanced optical readout of a single solid-state spin, Shuo Sun, Hyochul Kim, Glenn S. Solomon and Edo Waks, manuscript in preparation.
University of Maryland, College Park
Protecting network traffic flow information using secure quantum routing (Theory)
Quantum networks enable unconditionally secure communication guaranteed by the laws of physics. The majority of quantum communication protocols to-date focus on securing the messages being transmitted from one point to another. When many quantum channels combine to form a complex network, however, the secrecy of messages transmitted between individual parties represents only one aspect of security. In many cases, knowledge of who is talking to whom in a network can reveal critical information. This realization lies at the heart of network traffic analysis, which focuses on using the flow of network data to extract useful information.
In our work, we demonstrate that a quantum network can protect the identity of senders and receivers from an external wiretapper. We propose a protocol, referred as secure quantum routing, which fully protects the identity of a sender and receiver, as well as the content of the message simultaneously from an eavesdropper that has access to all communication across the network. The secure quantum routing protocol has the significant advantage that it can be realized by using only linear optical elements that efficiently generates, transmits and detects single photons, which is compatible with currently available technological capabilities. Our protocol provides compelling approach to extend conventional point to point quantum communication to more complex network settings to attain quantum advantages over classical networks.
Secure quantum routing without entanglement, Shuo Sun and Edo Waks, arXiv:1607.03163 (2016).
University of Maryland, College Park
- Single-shot optical readout of a quantum bit using cavity quantum electrodynamics PHYSICAL REVIEW A 2016; 94 (1)
A quantum phase switch between a single solid-state spin and a photon
2016; 11 (6): 539-?
Interactions between single spins and photons are essential for quantum networks and distributed quantum computation. Achieving spin-photon interactions in a solid-state device could enable compact chip-integrated quantum circuits operating at gigahertz bandwidths. Many theoretical works have suggested using spins embedded in nanophotonic structures to attain this high-speed interface. These proposals implement a quantum switch where the spin flips the state of the photon and a photon flips the spin state. However, such a switch has not yet been realized using a solid-state spin system. Here, we report an experimental realization of a spin-photon quantum switch using a single solid-state spin embedded in a nanophotonic cavity. We show that the spin state strongly modulates the polarization of a reflected photon, and a single reflected photon coherently rotates the spin state. These strong spin-photon interactions open up a promising direction for solid-state implementations of high-speed quantum networks and on-chip quantum information processors using nanophotonic devices.
View details for DOI 10.1038/NNANO.2015.334
View details for Web of Science ID 000377476800013
View details for PubMedID 26854569
- Deterministic generation of entanglement between a quantum-dot spin and a photon PHYSICAL REVIEW A 2014; 90 (4)
- Strain tuning of a quantum dot strongly coupled to a photonic crystal cavity APPLIED PHYSICS LETTERS 2013; 103 (15)
- Microtube's Tapers Affect its Subwavelength Focusing Effect 2011 INTERNATIONAL CONFERENCE ON PHYSICS SCIENCE AND TECHNOLOGY (ICPST) 2011; 22: 505-511