Gyunghun Kim

Analog quantum simulation of paraparticle statistics

  1. Gyunghun Kim,
  2. Cora N. Barrett,
  3. Sarah E. Muschinske,
  4. Junyoung An,
  5. Helin Zhang,
  6. Ilan T. Rosen,
  7. Rabindra Das,
  8. Michael A. Gingras,
  9. David K. Kim,
  10. Bethany M. Niedzielski,
  11. Meghan Schuldt,
  12. Jonilyn L. Yoder,
  13. Mollie E. Schwartz,
  14. Kyle Serniak,
  15. Jeffrey A. Grover,
  16. Max Hays,
  17. and William D. Oliver
Bosonic and fermionic quantum statistics describe all known elementary and emergent particles in three dimensions, although many attempts have been made to discover other valid quantum
statistical frameworks. One recent formulation proposes „R-paraparticles,“ indistinguishable particles with nonlocal internal degrees of freedom governed by generalized exchange rules [Wang and Hazzard, Nature 637, 314 (2025)]. Here, we emulate a species of paraparticle that exhibits a generalized Pauli exclusion principle using a superconducting qubit lattice. We confirm its unique quantum statistics by measuring a 180∘ phase shift under paraparticle exchange, observing antibunching independent of internal degrees of freedom under two-particle interference at a beamsplitter, and finding a thermal occupation inconsistent with both Bose-Einstein and Fermi-Dirac statistics. These results demonstrate that parastatistics are observable on quantum simulation platforms, further motivating their use to explore theorized new phases of matter.
arxiv pdf

Characterization of Broadband Purcell Filters with Compact Footprint for Fast Multiplexed Superconducting Qubit Readout

  1. Seong Hyeon Park,
  2. Gahyun Choi,
  3. Gyunghun Kim,
  4. Jaehyeong Jo,
  5. Bumsung Lee,
  6. Geonyoung Kim,
  7. Kibog Park,
  8. Yong-Ho Lee,
  9. and Seungyong Hahn
Engineering the admittance of external environments connected to superconducting qubits is essential, as increasing the measurement speed introduces spontaneous emission loss to superconducting
qubits, known as Purcell loss. Here, we report a broad bandwidth Purcell filter design within a small footprint, which effectively suppresses Purcell loss without losing the fast measurement speed. We characterize the filter’s frequency response at 4.3 K and also estimate Purcell loss suppression by finite-element-method simulations of superconducting planar circuit layouts with the proposed filter design. The measured bandwidth is over 790 MHz within 0.29 mm2 while the estimated lifetime enhancement can be over 5000 times with multiple Purcell filters. The presented filter design is expected to be easily integrated on existing superconducting quantum circuits for fast and multiplexed readout without occupying large footprint.
arxiv pdf