# Ancilla-assisted quantum process tomography.

@article{Altepeter2003AncillaassistedQP, title={Ancilla-assisted quantum process tomography.}, author={Joseph Altepeter and David Branning and Evan Jeffrey and Tzu-Chieh Wei and Paul G. Kwiat and Rob Thew and Jeremy Lloyd O'Brien and Michael A. Nielsen and A. G. White}, journal={Physical review letters}, year={2003}, volume={90 19}, pages={ 193601 } }

Complete and precise characterization of a quantum dynamical process can be achieved via the method of quantum process tomography. Using a source of correlated photons, we have implemented several methods, each investigating a wide range of processes, e.g., unitary, decohering, and polarizing. One of these methods, ancilla-assisted process tomography (AAPT), makes use of an additional "ancilla system," and we have theoretically determined the conditions when AAPT is possible. Surprisingly…

## 177 Citations

### Complete Characterization of Quantum-Optical Processes

- PhysicsScience
- 2008

This work presents a method for characterizing, with arbitrarily high accuracy, any quantum optical process by studying, via homodyne tomography, its effect on a set of coherent states, that is, classical fields produced by common laser sources.

### Direct and Parallel Tomography of a Quantum Process

- Physics
- 2013

As the method to completely characterize quantum dynamical processes, quantum process tomography (QPT) is vitally important for quantum information processing and quantum control, where the…

### Experimental realization of direct characterization of quantum dynamics

- Physics
- 2007

We experimentally implement direct characterization of quantum dynamics (DCQD) algorithm of a single qubit proposed in M. Mohseni and D. A. Lidar [Phys. Rev. Lett. 97, 170501 (2006)], which does not…

### Quantum Process Tomography: Resource Analysis of Different Strategies

- Physics
- 2008

Characterization of quantum dynamics is a fundamental problem in quantum physics and quantuminformation science. Several methods are known which achieve this goal, namely standard quantum-process…

### Two-qubit decoherence mechanisms revealed via quantum process tomography

- Physics
- 2009

We analyze the quantum process tomography (QPT) in the presence of decoherence, focusing on distinguishing local and nonlocal decoherence mechanisms for a two-partite system from experimental QPT…

### Experimental characterization of quantum dynamics through many-body interactions.

- PhysicsPhysical review letters
- 2013

This work shows the first, complete characterization of single-qubit processes using a single generalized measurement realized through multibody correlations with three ancilla qubits, and all diagonal elements of the process matrix can be estimated with a single setting.

### 8 Characterization of Quantum Devices

- Physics
- 2004

Using quantum tomography and a single entangled state it is possible to characterize completely a quantum device, a channel, or a measuring apparatus. The method is very robust to imperfections of…

### Partial standard quantum process tomography

- PhysicsQuantum Inf. Process.
- 2013

A scheme to decide an arbitrary matrix element of χ, which is in the Choi matrix representation, in a scalable way in the general theory of standard quantum process tomography, and it is observed that to decide the diagonal matrix element, one just needs a single measurement.

### Direct characterization of quantum dynamics with noisy ancilla

- Physics
- 2015

We present methods for the direct characterization of quantum dynamics (DCQD) in which both the principal and ancilla systems undergo noisy processes. Using a concatenated error detection code, we…

### Selective and efficient quantum process tomography with single photons.

- PhysicsPhysical review letters
- 2010

The results of the first photonic implementation of a new method for quantum process tomography based on the idea of mapping the estimation of any chi-matrix element onto the average fidelity of a quantum channel and estimating the latter by sampling randomly over a special set of states called a 2-design are presented.

## References

SHOWING 1-10 OF 33 REFERENCES

### Phd by thesis

- Geography, Environmental ScienceNature
- 1988

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most…

### Phys. Rev. Lett

- Phys. Rev. Lett
- 1999

### Nature Phys. Rev. A

- Nature Phys. Rev. A
- 1998

### E2(|ψ >< ψ|)). This was calculated numerically for our reported results. See Bowdrey et al

- F(E1, E2) ≡ dψF (E1(|ψ >< ψ|)
- 2002

### Electronic address: kwiat@uiuc.edu † Group of Applied Physics

- Electronic address: kwiat@uiuc.edu † Group of Applied Physics
- 1211

### 13] F 1 ; 2 Tr

- 13] F 1 ; 2 Tr

### Private communications showed this work was in development as early as

- 2001

### Phys

- Rev. A 66, 012303
- 2002

### Phys

- Rev. A 64, 052312
- 2001

### Phys. Rev. Lett. Dür and J. I. Cirac, Phys. Rev. A

- Phys. Rev. Lett. Dür and J. I. Cirac, Phys. Rev. A
- 2001