News

Architecting noisy intermediate-scale trapped ion quantum computers

Architecting noisy intermediate-scale trapped ion quantum computers

New paper published in the International Symposium on Computer Architecture (ISCA2020)!

Critical faults of leakage errors on the surface code

Critical faults of leakage errors on the surface code

Leakage is a particularly damaging error that occurs when a qubit leaves the defined computational subspace. Leakage errors limit the effectiveness of quantum error correcting codes by spreading additional errors to other qubits and corrupting syndrome...

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

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 at QIP2020

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.  

Brown lab at SESAPS 2019

Brown lab at SESAPS 2019

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

Brown Lab at APQC Workshop

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.

Generating Fault-Tolerant Cluster States from Crystal Structures

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.

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

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.

Brown Lab at QEC19

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

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,...

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...

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...

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...

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 

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.