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Princeton University, Ph.D. 2016 Budapest University of Technology and Economics, M.Sc., B.Sc. 2010.
Andras has a Ph.D. in Physics from Princeton where he worked in the Yazdani lab working on strongly correlated and topological electronic systems. Currently,... Read more about Andras Gyenis
Professor at Princeton University Ph.D., Harvard University, 2005 B.S.E., Electrical Engineering, Princeton University, 2000
Quantum mechanics has played an ever-increasing role in electronics over the past several decades. At first, materials and devices were introduced that...
PhD 2015, Physics, Ecole Fédérale Polytechnique de Lausanne
Berthold received his PhD in physics from the Ecole Fédérale Polytechnique de Lausanne in 2015. He joined the Physics Department at Princeton University as a... Read more about Berthold Jaeck
B.Tech in Engineering Physics, Indian Institute of Technology Bombay (2020) M.Tech in Engineering Physics with specialization in Nanoscience, Indian Institute of Technology Bombay (2020)
Parth is a second year graduate student originating from Mumbai, India. He is currently working on developing architectures that protect qubit from... Read more about Parth Jatakia
Inci is a second year undergraduate student at Princeton University from Istanbul, Turkey. She works on characterizing qubits with embedded qubit control... Read more about Inci Karaaslan
Alicia Kollár was a Princeton Materials Science Postdoctoral Fellowship with Andrew Houck from 2017-2019, working on quantum simulation of solid-state physics... Read more about Alicia Kollár
Lev is a Postdoctoral Research Associate. He did his PhD in Rob Schoelkopf's lab, studying superconducting thin-film 3D resonators for quantum information... Read more about Lev Krayzman
BS & MS, Physics, Indian Institute of Science Education and Research, Mohali (2021)
Shashwat is a first-year graduate student in ECE from Bijnor, India. He completed his bachelor's and master's degrees in Physics from the Indian Institute of... Read more about Shashwat Kumar
Hoang is a senior in Electrical Engineering at Princeton with a certificate in Engineering Physics. He explores novel qubit species with better encoding scheme... Read more about Hoang Le
Zhaoqi Leng joined the lab in 2015. He worked on creating and stabilizing entanglement in circuit QED systems. He is researching new optimization/machine... Read more about Zhaoqi Leng
Jeronimo is a second year graduate student on the quantum simulation side of the group working on ultrastrong coupling to photonic crystals as well as... Read more about Jeronimo Martinez
Connie studied Physics with a a certificate in Applications of Computing. For her thesis, she is working on designing a more fault-tolerant zero-pi qubit.... Read more about Connie Miao
Near-term quantum computers are primarily limited by errors in quantum operations (or gates) between two quantum bits (or qubits). A physical machine typically provides a set of basis gates that include primitive 2-qubit (2Q) and 1-qubit (1Q) gates that can be implemented in a given technology. 2Q entangling gates, coupled with some 1Q gates, allow for universal quantum computation. In superconducting technologies, the current state of the art is to implement the same 2Q gate between every pair of qubits (typically an XX- or XY-type gate). This strict hardware uniformity requirement for 2Q gates in a large quantum computer has made scaling up a time and resource-intensive endeavor in the lab. We propose a radical idea -- allow the 2Q basis gate(s) to differ between every pair of qubits, selecting the best entangling gates that can be calibrated between given pairs of qubits. This work aims to give quantum scientists the ability to run meaningful algorithms with qubit systems that are not perfectly uniform. Scientists will also be able to use a much broader variety of novel 2Q gates for quantum computing. We develop a theoretical framework for identifying good 2Q basis gates on "nonstandard" Cartan trajectories that deviate from "standard" trajectories like XX. We then introduce practical methods for calibration and compilation with nonstandard 2Q gates, and discuss possible ways to improve the compilation. To demonstrate our methods in a case study, we simulated both standard XY-type trajectories and faster, nonstandard trajectories using an entangling gate architecture with far-detuned transmon qubits. We identify efficient 2Q basis gates on these nonstandard trajectories and use them to compile a number of standard benchmark circuits such as QFT and QAOA. Our results demonstrate an 8x improvement over the baseline 2Q gates with respect to speed and coherence-limited gate fidelity.
Recent theoretical work has highlighted that quantizing a superconducting circuit in the presence of time- dependent flux Φ(t) generally produces Hamiltonian terms proportional to dΦ/dt unless a special allocation of the flux across inductive terms is chosen. Here, we present an experiment probing the effects of a fast flux ramp applied to a heavy-fluxonium circuit. The experiment confirms that na ̈ıve omission of the dΦ/dt term leads to theoretical predictions inconsistent with experimental data. Experimental data are fully consistent with recent theory that includes the derivative term or equivalently uses “irrotational variables” that uniquely allocate the flux to properly eliminate the dΦ/dt term.
We introduce a Xilinx RF System-on-Chip (RFSoC)-based qubit controller (called the Quantum Instrumentation Control Kit, or QICK for short), which supports the direct synthesis of control pulses with carrier frequencies of up to 6 GHz. The QICK can control multiple qubits or other quantum devices. The QICK consists of a digital board hosting an RFSoC field-programmable gate array, custom firmware, and software and an optional companion custom-designed analog front-end board. We characterize the analog performance of the system as well as its digital latency, important for quantum error correction and feedback protocols. We benchmark the controller by performing standard characterizations of a transmon qubit. We achieve an average gate fidelity of F=99.93%. All of the schematics, firmware, and software are open-source.
The origin of many quantum-material phenomena is intimately related to the presence of flat electronic bands. In quantum simulation, such bands have been realized through line-graph lattices, a class of lattices known to exhibit flat bands. Based on that work, we conduct a high-throughput screening for line-graph lattices among the crystalline structures of the Materials Flatband Database and report on new candidates for line-graph materials and lattice models. In particular, we find materials with line-graph-lattice structures beyond the two most commonly known examples, the kagomé and pyrochlore lattices. We also identify materials which may exhibit flat topological bands. Finally, we examine the various line-graph lattices detected and highlight those with gapped flat bands and those most frequently represented among this set of materials. With the identification of real stoichiometric materials and theoretical lattice geometries, the results of this work may inform future studies of flat-band many-body physics in both condensed matter experiment and theory.
