coherent states - 2025 ACF Winter

Question

The squeeze operator can act upon these states to change the width of the wavepacket. For 10 points each:

[10h] Name these quantum states that are eigenvalues of the annihilation operator and saturate the uncertainty principle. These states are usually indexed by a complex value notated alpha.

ANSWER: coherent states [accept squeezed coherent states]

[10e] Coherent states are states of this quantum system, an analogue of a mass on a spring with a quadratic potential.

ANSWER: quantum harmonic oscillator [accept QHO; prompt on oscillator]

[10m] Since coherent states saturate the uncertainty principle, the product of the uncertainties in position and momentum must be equal to this number.

ANSWER: reduced Planck’s constant over 2 [or h-bar over 2; accept h over 4 pi; accept Planck’s constant over 4 pi; reject “Planck’s constant” or “h” or “h-bar” or “h over 2” or “Planck’s constant over 2”]

<Editors, Physics>

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Summary


California	Main	Y	4	17.50	100%	50%	25%
Canada	Main	Y	6	16.67	100%	50%	17%
Florida	Main	Y	12	8.33	42%	33%	8%
Great Lakes	Main	Y	3	3.33	33%	0%	0%
Overflow	Main	Y	1	20.00	100%	100%	0%
Pacific Northwest	Main	Y	10	14.00	80%	50%	10%
South Central	Main	Y	5	8.00	40%	40%	0%
UK	Main	Y	4	20.00	100%	75%	25%
Upper Mid-Atlantic	Main	Y	8	10.00	75%	25%	0%
Upstate NY	Main	Y	8	7.50	75%	0%	0%
2025 ACF Nationals	2025-08-09	Y	9	15.56	67%	78%	11%

Data


Berkeley A	Berkeley E	0	10	0	10
Stanford A	Berkeley B	10	10	0	20
Stanford B	Berkeley C	0	10	10	20
Berkeley D	Stanford C	0	10	10	20
Claremont Scripps	UCI	0	10	10	20
UCLA B	USC	0	10	10	20
UCSB	UCLA C	0	10	0	10
UCLA A	UCSD Two Running Violet V Forms	10	10	0	20
UCLA D	UCSD Vices and Virtues	0	10	0	10
UCSD What Hath God Wrought	Claremont Pitzer	0	10	10	20
Guelph B	Toronto F	0	0	0	0
Toronto H	McGill A	0	0	10	10
Carleton	McMaster A	0	10	10	20
Guelph A	McMaster B	0	0	0	0
Toronto C	McMaster C	0	10	0	10
Queen's B	Toronto E	0	10	0	10
McGill C	Toronto A	0	10	0	10
Toronto B	Toronto I	10	0	10	20
McGill B	Toronto D	0	10	10	20
Waterloo	Toronto J	0	0	0	0
Toronto K	Ottawa	0	0	0	0
Toronto Metropolitan	Western Ontario	0	0	0	0
FIU	UF B	0	0	0	0
UCF A	UCF B	0	10	0	10
UF A	UF E	0	0	0	0
WashU A	Missouri A	0	10	10	20
Purdue C	Chicago B	0	0	0	0
Michigan B	Chicago C	0	10	0	10
Notre Dame D	Illinois B	0	10	0	10
Louisville A	Chicago D	0	10	10	20
Louisville B	Notre Dame C	0	10	10	20
Michigan A	Notre Dame A	0	10	10	20
UIC	Michigan C	0	0	0	0
Indiana A	Notre Dame B	10	10	10	30
Kentucky	Purdue A	0	10	10	20
Illinois C	Purdue B	0	10	0	10
St. Thomas	Macalester A	0	10	0	10
Macalester B	Carleton	0	0	10	10
Minnesota B	Minnesota A	0	0	0	0
Nebraska	Minnesota C	0	0	0	0
British Columbia B	Alberta	0	10	0	10
British Columbia A	British Columbia C	0	10	10	20
Washington A	British Columbia D	0	10	10	20
Simon Fraser	Washington B	10	10	10	30
Iowa State	Wisconsin	0	10	10	20
McGill D	Arizona State A	0	10	0	10
Northwestern C	Arizona State B	0	10	0	10
Ohio	Rose State	0	0	0	0
Texas A	Texas B	0	10	0	10
Iowa	Tulsa	0	0	0	0
Alberta B	UCO	0	10	10	20
UTD A	UTD B	0	10	10	20
UAB A	Alabama B	0	10	0	10
Auburn A	Georgia Tech D	0	10	0	10
Auburn B	Sewanee A	0	0	0	0
Vanderbilt A	Bruin A	0	10	0	10
Georgia Tech B	Georgia Tech A	0	10	0	10
Georgia Tech C	Vanderbilt B	0	10	0	10
Huntsville A	Huntsville B	0	0	0	0
Alabama A	Mississippi State A	0	10	0	10
Northwestern B	Northwestern A	0	10	0	10
Cambridge C	Bristol B	0	10	10	20
Imperial A	Sheffield B	0	10	10	20
Imperial B	LSE A	10	10	10	30
Durham B	Manchester A	0	0	0	0
Oxford A	Southampton A	0	10	10	20
Durham A	Sheffield A	0	10	10	20
Imperial C	Sheffield C	0	0	10	10
Oxford B	Southampton B	0	10	10	20
City St George's A	Cambridge B	0	0	0	0