In the News


March 12, 2020

Photon-mediated charge-exchange reactions between 39K atoms and 40Ca+ ions in a hybrid trap

Our detailed study of photon-mediated charge exchange between cold Potassium atoms and calcium ions is published in the journal Physical Chemistry Chemical Physics.

Brown Lab

January 13, 2020

Brown Lab at QIP2020

Brown lab at QIP2020 in Shenzhen. Posters about quantum error correction by Natalie, Shilin, Dripto, and Muyuan. Talks about quantum error correction by Mike and Ken.


November 13, 2019

Brown lab at SESAPS 2019

Brown lab attended the Southeastern Section of the American Physical Society (SESAPS) in Wilmington.

Spectator qubit poster at APQC

October 18, 2019

Brown Lab at APQC Workshop

Swarnadeep Majumder attended the Assessing Performance of Quantum Computers (APQC) workshop in Estes Park, CO and presented a poster on Real Tiime Calibration Using Spectator Qubits.


October 17, 2019

Generating Fault-Tolerant Cluster States from Crystal Structures

Quantum information is delicate. To preserve it, we must constantly interact with our system in order to remove errors.


August 5, 2019

A hybrid ion-atom trap with integrated high resolution mass spectrometer

Cold molecular ions are good candidates for precision measurements such as the time variation of proton to electron mass ratio.

August 4, 2019

Brown Lab at QEC19

Brown lab attended the 5th International Conference on Quantum Error Correction in London.

July 16, 2019

Watching the Errors with Spectator Qubits

Quantum computers promise to be a technological revolution, but they will only be possible if the error rate of quantum bits (qubits) is kept under a manageable level. Many techniques have been developed to control, mitigate, and correct quantum errors, and the most appropriate choice depends [...]

June 4, 2019

Brown Lab at TQC + NISQ

Ken Brown and Swarnadeep Majumder attend TQC 2019 conference + NISQ workshop.  Ken presents an invited talk on Error Reduction, Fault Tolerance, and Scalability at TQC.  Swarnadeep presents a poster on real-time calibration with spectator qubits at the NISQ workshop. 

May 14, 2019

Leakage Mitigation Using Quantum Error Correction in a Mixed Ion Scheme

  Mixed species surface code layout. Hyperfine (171Yb+) ions are defined as ancilla qubits (white) and Zeeman (174Yb+) ions are defined as data qubits (black). The green (blue) diamond represents an X (Z) stabilizer measurement.   Leakage errors are exceptionally damaging errors that occur when a [...]

March 12, 2019

Handling Leakage with Subsystem Codes

The distance-3 and distance-5 rotated subsystem surface codes.  Although the weight-6 rectangular stabilizers are larger than the weight-4 stabilizer of the surface code, they can be measured in pairs of triangular gauge operators.  This locality limits correlated errors due to leakage, resulting [...]

February 27, 2019

Brown Lab at March Meeting

We are presenting two talks at the APS March Meeting: Leonardo de Castro, A28.00005 Characterizing Unwanted Motional Coupling in Mølmer-Sørensen Gates Dripto Debroy, L27.00005 Stabilizer Slicing: Coherent Error Cancellations in LDPC Codes 

February 10, 2019

Prof. Brown speaks at the Carolina Science Cafe

Ken spoke to the Carolina Science Cafe about Practical Quantum Computing on Feb. 6. It was a packed room at the Back Bar at Top of the Hill in Chapel Hill, North Carolina. 

January 14, 2019

Brown Lab at QIP

Brown lab members present four posters at the 22nd Annual Conference on Quantum Information Processing #15 Symmetric vs. bosonic extension for bipartite states, Youning Li, Shilin Huang, Dong Ruan and Bei Zeng  #81 2-D Compass Codes, Muyuan Li, Michael Newman, Daniel Miller, Kenneth Brown and Yukai [...]

December 18, 2018

Stabilizer Slicing is published in Physical Review Letters

Our manuscript "Stabilizer Slicing: Coherent error cancellations in low-density parity-check codes" has been published in Physical Review Letters and can be found here. This work describes a method to cancel out coherent overrotation errors that are applied during quantum error correction.    (Top [...]