APS March Meeting 2023: QM’s Scientific Lineup
The holiday season may be behind us, but for us physicists, the real fun is still ahead: the annual APS March Meeting! This time, we will meet you in person in Las Vegas, Nevada.
If you are planning on attending APS March this year, be sure to swing by booth #613 and meet the Quantum Machines team. Not only will you have the opportunity to see live demonstrations of our quantum control and quantum electronics products, but you’ll also be able to play with them on your own and learn how they can help you take your quantum computing experiments and research to the next level.
But wait, there’s more! Our team of physicists and engineers has prepared an impressive scientific lineup for the upcoming Meeting. From error mitigation via adaptive calibrations to universal qubit control and adaptive Shor Scheme for fault tolerance on repetition code, you’ll want to add these talks to your calendars. Keep reading to learn more about the scientific talks, abstracts, and schedule.
Error mitigation via adaptive calibrations
Presenter: Lior Ella
Abstract: Feedback and adaptivity play an increasingly important role in quantum circuit execution [1-3]. These mechanisms can be applied both during circuit execution, where timing requirements are extremely stringent due to limited coherence times, as well as between circuit executions, where timing requirements play an important role due to 1/f noise and parameter drift. In this talk, we show how algorithms such as iterative phase estimation, entangled 2-qubit states, and iterative state preparation techniques can be used as highly-sensitive probes to significantly speed up calibration and characterization workflows for superconducting qubit platforms. This results in higher circuit performance due to the ability to track drifting qubit parameters with much less overhead than traditional, non-feedback-based methods. Furthermore, these ideas can be expanded to be used during quantum error correction cycles to detect and prevent in-situ parameter drift during ancilla measurement rounds.
[1] A. D. Córcoles, et al, Phys. Rev. Lett. 127, 100501 (2021)
[2] Christophe Piveteau, David Sutter, arXiv:2205.00016 (2022)
[3] Cassandra Granade, Nathan Wiebe, arXiv:2208.04526 (2022)
When: Monday, March 6, 12:30 PM (Room 406)
Crossing the QASM: gate level compilation for practical quantum control
Presenter: Dor Israeli
Abstract: With the quantum computing ecosystem growing substantially in qubit technologies, cloud-accessible solutions, and programming languages, it becomes increasingly important to rely on and develop high-level interface standards like OpenQASM3. Towards standardization of programming languages to describe quantum circuit models, we must indeed be able to link applications to pulse-level languages, which are highly dependent on the underlying physical system. Here, we showcase an effective and convenient software interface for controlling the physical layer, connecting the OpenQASM3 standard to QUA, the pulse-level language of the Quantum Orchestration Platform. Once configured, our compiler provides the ability to write an algorithm on a gate-level abstraction and run it on different real devices and qubits. We highlight the currently supported features and their usage, from control flow to parametric executions, cross-embedding of OpenQASM3 and QUA, channel scheduling, semantic optimization and automatic qubit allocation. This compiler is critical in enabling the rich quantum ecosystem and its promises for society.
When: Tuesday, March 7, 9:12 AM (Room 409)
Path to scaleup technologies for cryogenic quantum computing platforms
Presenter: Yaniv Kurman
Abstract: Scaling up the number of qubits in quantum computers is essential for reaching useful quantum computing. One fundamental limitation on the number of qubits in cryogenic platforms, such as superconducting circuits and semiconductor quantum dots, is due to the heat load capacity of dilution fridges and the power consumption per qubit. It was shown recently by Wallraff et al. [1] that engineering commercial cryogenic setups in terms of attenuator distributions, and cabling choice can enable the support of 100 qubits. In this proposal, we present a system-level end-to-end analysis of the different technological avenues toward the scaling of commercially available cryogenic platforms for quantum computers. We overview and compare the requirements and limitations of current state-of-the-art systems and analyze the next-generation development in the field of cryogenic cabling and electronics. In such systems, we expect to at least double the qubit capacity of commercial dilution fridges in the near future.
[1] Krinner, Sebastian, et al. EPJ Quantum Technology 6.1 (2019).
When: Tuesday, March 7, 2:00 PM
Universal qubit control through FPGA-accelerated qubit classification, Hamiltonian estimation and real-time feedback [Part 1]
Presenter: Joost van der Heijden
Abstract: Gate-controlled spin qubits are a promising platform for implementing quantum processors [1,2] and now operate near the error-correctable threshold [3]. To correct errors, however, fast real-time feedback based on qubit measurements must be executed within the coherence time of the qubits. Moreover, continuous real-time feedback is also useful to tune and calibrate the qubit environment in order to maintain high-fidelity gates and long coherence times.
Here, we read out singlet-triplet qubits in GaAs double quantum dots by radio-frequency reflectometry without analog demodulation/thresholding. Instead, qubit classification is performed in real-time on an FPGA-based pulse processor (Quantum Machines’ OPX+ [4]) using the raw reflectometry signal of the cryostat, opening the door to on-the-fly adaptive control sequences such as Hamiltonian estimation and qubit stabilization. To this end, we show how the co-integration of an OPX+ and QDevil’s QDAC [5] can be used to optimize qubit tuning voltages in real-time, based on single-shot outcomes of qubit manipulations.
[1] A.M.J. Zwerver et al., Nat. Electron. 5, 184-190 (2022)
[2] S.G.J. Philips et al., Nature 609, 919-924 (2022)
[3] A. Noiri et al., Nature 601, 338–342 (2022)
[4] https://www.quantum-machines.co/opx+/
[5] https://www.quantum-machines.co/qdevil
*This project was funded within the QuantERA II Programme that has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No 101017733.
When: Wednesday, March 8, 9:48 AM (Room 403/404)
Temperature Performance of Magnetic Shielding for Multi-Qubit Chip Carrier
Presenter: Soren Andresen
Abstract: Quantum error correction for fault-tolerant quantum computing will require dense one- and two-qubit gate sequences with minimal generation of noise and heating effects. Flux-tunable superconducting qubits have recently been implemented in a surface-code-inspired geometry [1], utilizing frequency tuning and short gate operations at the cost of increased flux-bias noise [2]. Overall, microwave and magnetic shielding is considered crucial for achieving high coherence and fidelity in a wide variety of superconducting qubit experiments.
In this work we introduce a magnetic shielding for our multi-qubit chip carrier: QCage.24. The shielding is a fully EMC tight assembly composed of layers of mu-metal and bulk aluminum. Since thermalization of the qubit chip is of the utmost importance to increase coherence times, we show that our solution enables cooling down below 50 mK with a minimal time delay. Optimal heat sinking to the mixing chamber plate is achieved, showing recovery times of about 15 minutes after induced heating is applied. Eventually, no heating effects were observed at the sample mount inside the shielding when inducing magnetic heating in the outer mu-metal shield.
[1] Krinner, S. et al., Nature 605, 669 (2022)
[2] Kjaergaard, M. et al., Annual Review of Condensed Matter Physics 11, 369 (2020)
When: Wednesday, March 8, 4:12 PM (Room 406)
Characterization of Chip Packaging for Multi-Qubit Quantum Processors
Presenter: Merlin von Soosten
Abstract: Nowadays, Noisy Intermediate-Scale Quantum (NISQ) superconducting hardware are widely used to demonstrate surface codes algorithm as well as quantum simulators implementation [1,2]. However, despite having achieved single and two-qubit gates with fidelity above the surface code threshold limit [3], further improvement is required to reduce the number of physical qubits that will be required to operate a fault-tolerant quantum computer.
In this talk we present the results from our newest multi-qubit chip packaging solution: QCage.24 [4]. By implementing a recently developed microwave calibration technique operated at 40 mK [5,6], we can assess the reflection and transmission from the fridge wiring interface. We demonstrate reflection levels below 30 dB in the 4 – 8 GHz frequency bandwidth. Furthermore, by knowing the transfer function, we simulated gate fidelities with four orders of magnitude improvement compared to the non-optimized chip packaging solution (i.e., reflection values in the order of 15 dB).
[1] Krinner, S. et al., Nature 605, 669 (2022)
[2] Mi, X. et al., Nature 601, 531 (2022)
[3] Kjaergaard, M. et al., Annual Review of Condensed Matter Physics 11, 369 (2020)
[4] https://qdevil.com/qcage-microwave-cavity-sample-holder/
[5] Wang, H. et al., Quantum Sci.Technol. 6, 035015 (2021)
[6] Simbierowicz, S. et al., Applied Physics Letters 120, 054004 (2022)
When: Wednesday, March 8, 4:48 PM, (Room 406)
Adaptive Shor Scheme for fault tolerance on repetition code
Presenter: Yaniv Kurman
Abstract: Quantum error correction schemes are essential for reaching fault-tolerant quantum computing. However, fault-tolerant schemes require significant overhead that by itself introduces additional errors. The Shor scheme tackles this problem by repeating syndromes, which can reach (t+1)^2 measurement rounds for a stabilizer code that can correct up to t errors. A recent proposal of adaptive syndrome measurement for Shor schemes [1] suggests a protocol that requires no more than (t+3)^2/4-1 measurement rounds, significantly less than the regular Shor scheme. The adaptive measurement determines the syndrome for error correction based on the difference between consecutive rounds while keeping fault tolerance criteria. Thus, the adaptive scheme reaches its superiority by including classical calculation and decision-making during quantum calculation. In this work, we present the first simulation results of the adaptive Shor scheme and verify that it is indeed fault tolerant. We exemplify these results with a repetition code and indicate the requirements for implementing such fault-tolerant schemes in a physical system.
[1] Theerapat Tansuwannont, Kenneth R. Brown, arXiv:2208.05601 (2022)
When: Thursday, March 9, 3:36 PM (Room 406)
