#### LTAT.04.004

## Quantum Seminar

The Quantum Seminar is for master's students who want to specialize in quantum crypto, quantum computing, or quantum communication.

Most topics require both graduate-level math and quantum information basics (LTAT.04.008 (Introduction to) *Quantum Algorithms* and/or MTAT.07.024 *Quantum Crypto*).

#### Organization

- Talks are 80 min + questions
- Taking
`LTAT.00.008 Theoretical Informatics Project`

(3 ECTS) in parallel is encouraged (to implement stuff that's in your seminar paper; talk to your seminar supervisor!) - There's a class meeting in the beginning of the semester, and the talks are near the end of the semester.
- Meeting times will be discussed with the participants
- All course meetings are online-only.

## Topic Areas

- Quantum Crypto (Prof. Unruh)
- Quantum Computing Theory (Prof. Unruh)
- Quantum Algorithms (Assoc. Prof. Theis)
- Quantum Error Correcting Codes (Assoc. Profs. Skachek & Theis)
- Quantum information processing & transmission with light & photons (Assoc. Prof. Theis)
- Miscellaneous quantum computing

## Some specific topics

### 1. Quantum Crypto

(Will be discussed in first seminar meeting.)

### 2. Quantum Computing Theory

(Will be discussed in first seminar meeting.)

### 3. Quantum Algorithms

##### Quantum coupon collector

- Reference: arXiv:2002.07688
- Abstract: Classical coupon collector can be formulated as follows: given each cereal box contains a coupon and there are altogether k different coupons what is the expected number of boxes you have to buy in order to collect all different coupons. More formally, given uniformly random samples from a subset S of [n] of size k, what is the expected number of samples needed to identify S with high probability. The classical algorithm proposes k*log(k) number samples. However given certain assumptions on n and k the amount of quantum samples required can be asymptotically reduced.
- Supervisor: Evgenii Dolzhkov

##### Adversary lower bound for the k-sum problem

- Reference: arXiv:1206.6528
- Abstract: The paper presents a proof for a tight query lower bound on the problem of deciding whether there exist k numbers among n that sum up to a prescribed number, provided that the alphabet size is sufficiently large. Mathematical techniques used there are rather interesting, however there are no advanced theories used, so the paper should be rather understandable.
- Supervisor: Evgenii Dolzhkov

##### (More quantum algorithm topics in the first seminar meeting.)

### 4. Quantum Error Correcting Codes

##### A pedestrian view on quantum error correction

- Reference: Chapter 5 in Mermin
*Quantum Computer Science. An Introduction.*(2007) - Overview: The Miracle of Quantum Error Correction; Simplified Example; Physics of Error Generation; Diagnosing Error Syndromes; 5-Qbit Error-Correcting Code; 7-Qbit Error-Correcting Code; Operations On 7-Qbit Codewords; 7-Qbit Encoding Circuit; 5-Qbit Encoding Circuit.
- Supervisor: Javier Gil Vidal

##### (More QEC topics in the first seminar meeting.)

### 5. Quantum information processing & transmission with light & photons

(Topics will be presented in the first seminar meeting.)

### 6. Miscellaneous quantum computing

(Topic related to external internships/projects of QC students.)

See ya!